MEMCAL    ^SCHOOL 


John  l«Iar shall  Mlliamson 
Memorial 


Digitized  by  the  Internet  Archive 

in  2007  with  funding  from 

Microsoft  Corporation 


i 

http://www.archive.org/details/anatomyphysiologOOIewirich         I. 


A^ 


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ANATOMY 

AND  PHYSIOLOGY 

FOR  NURSES 


leroy  Lewis,  m.d. 

LATH    SURGEON    TO    AND    LECTURER    ON    ANATOMY    AND    PHYSIOLOGY 
FOR     NURSES      AT      THE      LEWIS      HOSPITAL,     BAY      CITY,      MICHIGAN 


Third  Edition,  Thoroughly  Revised 


PHILADELPHIA  AND  LONDON 

W.  B.  SAUNDERS  COMPANY 


r^ 


Copyright,    1905,    by  W.   B.    Saunders  and   Company.      Reprinted   Janu- 
ary,  1906,  April,  1907,  August,  1908,  and  February,  1909.      Re- 
vised, reprinted,    and    recopyrighted    January,   1910. 
Reprinted  September,  1910,  and  January,  1912. 
Revised,   entirely    reset,    reprinted,   and 
recopyrighted  September,  1913. 


Copyright,  1 913,  by  \V.  B.  Saunders  Company. 


Reprinted  September,  1914 


PRINTED    IN    AMERICA 


^;?f  ss  pF     ^ 

S  A  U  N  D  EfJ  8",COMrOAN»r 
PHlii^DCLPI-llA     '    ; 


/    k-i 


PREFACE  TO  THIRD  EDITION. 


The  first  edition  of  this  work  was  written  by  the  late 
Dr.  Le  Roy  Lewis  upon  the  request  of  many  of  those 
whom  he  had  instructed  in  anatomy  and  physiology. 
He  endeavored  to  make  the  text  as  simple  and  com- 
prehensive as  possible,  so  that  students  might  be  able 
to  grasp  the  primary  principles,  after  which  he  felt  that 
they  would  be  sufficiently  equipped  to  apply  themselves 
to  future  studies. 

The  works  of  Gray,  Wilson,  Deaver,  Brubaker,  Kim- 
ber,  and  others  were  freely  consulted,  and  in  some  in- 
stances their  language  was  employed  or  paraphrased. 
The  publishers  furnished  many  illustrations,  which  eluci- 
date the  text  and  aid  the  student  in  grasping  the  details 
of  the  subject. 

Owing  to  the  gratifying  reception  accorded  the  pre- 
vious editions  of  this  work,  the  present  editor  has  not 
deemed  it  wise  to  depart  materially  from  the  general 
plan  and  manner  of  presenting  the  subject.  Some  por- 
tions have  been  rewritten,  considerable  new  matter  has 
been  incorporated,  and  the  entire  book  has  been  thor- 
oughly revised.  It  is  hoped  that  this  new  edition  will 
be  found  to  be  particularly  adapted  to  the  needs  of 
students  and  practitioners  of  nursing. 


2S.j^t 


PREFACE, 


The  frequent  request,  on  the  part  of  those  whom 
it  has  been  my  pleasure  to  instruct  in  Anatomy  and 
Physiology  during  the  last  few  years,  to  write  a  book 
based  somewhat  upon  the  plan  employed  in  teaching 
this  subject  has  been  the  principal  incentive  to  my 
action. 

The  field  of  anatomy  and  physiology  is  already  too 
well  cultivated  for  one,  in  this  brief  space,  to  hope  to 
do  more  than  aid  the  student  in  acquiring  established 
facts. 

In  preparing  this  work  I  have  endeavored  to  make 
the  text  as  simple  and  comprehensive  as  could  be 
done,  that  the  students  may  be  able  to  grasp  the 
primary  principles,  after  which  they  will  have  suffi- 
cient knowledge  to  apply  themselves  to  future 
studies. 

The  works  of  Gray,  Wilson,  Deaver,  Brubaker, 
Kimber,  and  others  have  been  freely  consulted,  and 
in  some  instances  their  language  has  been  employed 
or  paraphrased. 

Through  the  kindness  of  the  publishers  I  have 
been  enabled  to  make  use  of  many  illustrations  that 


6  PREFACE. 

will  be  to  the  student  object-lessons   and   in   many- 
instances  make  the  text  more  comprehensive. 

The  author  desires  to  acknowledge  the  aid  derived 
from  the  sources  mentioned,  and  trusts  that  the 
reader  will  find  something  to  commend  in  the  pages 

that  follow. 

Leroy  lewis. 


CONTENTS. 


PAGB 

Introduction     «   ...... n 

CHAPTER  I. 

•  Osteology 13 

Classification  of  Bones 20 

The  Spinal  Column 22 

The  Skull 24 

Thorax  and  Pelvis    . 30 

Bones  of  the  Upper  Extremities 34 

The  Hand 37 

Bones  of  the  Lower  Extremities 38 

The  Foot 41 

The  Articulations 42 

Tendons 46 

Adipose  Tissue 47 

CHAPTER   n. 

*  The  Muscular  System 52 

Muscles  of  the  Head  and  Face 55 

Muscles  of  the  Neck 60 

Muscles  of  the  Trunk 64 

Muscles  of  the  Upper  Extremities 69 

Muscles  of  the  Shoulder  and  Arm 69 

Muscles  of  the  Forearm  .    , 72 

Muscles  of  the  Hand 74 

Muscles  of  the  Lower  Extremities     ........  76 

Muscles  of  the  Leg 82 

Muscles  of  the  Foot ....  84 

Muscles  of  the  Perineum 84 

7 


8  CONTENTS. 

CHAPTER   III. 


PAGE 


•The  Circulatory  or  Vascular  System 87 

The  Heart 87 

The  Arterial  System 94 

The  Aorta 96 

The  Thoracic  Aorta no 

The  Abdominal  Aorta m 

The  Venous  System 118 

Veins  of  the  Head  and  Neck 121 

Veins  of  the  Upper  Extremities 124 

Veins  of  the  Lower  Extremities 126 

Veins  of  the  Trunk 127 

The  Portal  Circulation 130 

The  Pulmonary  Circulation 130 

The  Blood 131 

The  Vascular  System  of  the  Fetus 138 

CHAPTER   IV. 

\The  Respiratory  System 144 

The  Lungs 145 

The  Diaphragm 153 

CHAPTER   V. 

'   The  Digestive  System    . «    .    .    .  154 

The  Esophagus  and  Stomach 162 

The  Intestines 165 

The  Lacteals 173 

The  Thoracic  Duct 175 

•  Regions  of  the  Abdomen  and  their  Contents  .    .    .177 

CHAPTER   VI.      - 

^  The  Excretory  System 180 

The  Kidneys 182 

The  Ureters 186 

The  Bladder 186 


CONTENTS.  9 

The  Excretory  System  (^Continued).  page 

The  Suprarenal  Capsule 190 

The  Skin 190 

The  Appendages  of  the  Skin 194 

CHAPTER   VII. 

The  Nervous  System log 

The  Nerves 203 

The  Brain 209 

The  Spinal  Cord 216 

The  Nerves  of  the  General  System 219 

The  Great  Sympathetic  Nerve 229 

CHAPTER   VIII. 

The  Glandular  System 233 

The  Lymphatic  Glands 233 

The  Liver 235 

The  Gall-bladder 237 

The  Spleen 237 

The  Pancreas 241 

The  Parotid  Glands 241 

The  Submaxillary  Glands 243 

The  Sublingual  Glands 243 

The  Thyroid  Gland 244 

The  Lacrimal  Glands 244 

The  Mesenteric  Glands .    , 245 

The  Mammary  Glands 246 

The  Sebaceous  Glands 247 

The  Sudoriparous  Glands 249 

CHAPTER   IX. 
The  Membranes  of  the  Body 251 

CHAPTER  X. 

The  Organs  of  Special  Sense 253 

The  Organs  of  Sight 253 


lO  CONTENTS, 

The  Organs  of  Special  Sense  {Continued)  page 

The  Appendages  of  the  Eye 258 

Physiology  of  Vision 260 

The  Organs  of  Hearing 261 

The  Organs  of  Taste 264 

The  Organs  of  Smell 266 

The  Organs  of  Touch 268 

CHAPTER   XI. 

The  Female  Organs  of  Generation 271 

The  Vagina 274 

The  Uterus 275 

Appendages  of  the  Uterus    c 279 

CHAPTER   XII. 

The  Male  Organs  of  Generation 287 

The  Prostate  Gland 287 

Covvper's  Glands 287 

The  Penis 287 

The  Testes 288 

The  Seminal  Vesicles 290 

Semen 291 

Impregnation 291 

CHAPTER  XIII. 
Repair  and  Waste — Nutrition — Animal  Heat — Perspi- 
ration— The   Power    that   Supports  and   Preserves 

Health ,    .  294 

Nutrition c    ......    .  296 

Animal  Heat .   297 

Perspiration 299 

The  Power  that  Supports  and  Preserves  Health  .   302 


Index .   .   .   o   »    .   .   „ 307 


Anatomy  and  Physiology 


FOR 


Nurses 


INTRODUCTION 

In  taking  up  the  study  of  the  anatomy  of  the  human 
body  we  shall  confine  ourselves  to  a  general  considera- 
tion of  those  branches  that  most  concern  the  nurse,  tak- 
ing up  the  anatomy  of  the  various  organs  and  their  physi- 
ologic functions,  and  omitting  the  minute  anatomy  that 
is  required  only  of  those  who  desire  to  perfect  them- 
selves in  advanced  work.  The  essential  points  that  a 
nurse  should  be  well  acquainted  with  are:  The  regions 
of  the  body;  the  internal  organs,  their  names  and  their 
location,  the  relation  each  organ  bears  to  life.  Thus 
only  will  we  be  enabled  to  understand  the  conditions  of 
the  body  in  disease. 

In  applying  ourselves  to  that  important  subject  that 
concerns  the  nursing  of  the  sick,  we  should  understand, 
first  what  goes  to  make  up  the  complex  organization  of 
the  body  and,  second,  by  what  means  we  are  to  obtain 
this  knowledge. 

We  shall  begin  our  first  study  by  taking  up  the  several 
systems  that  constitute  the  body,  so  that  the  nurse  may 

11 


12        ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

become  familiar  with  the  technical  terms  that  will  be 
employed  in  the  general  work: 

The  word  anatomy  is  derived  from  two  Greek  words, 
d.v6.,  apart,  and  T£[ii^£cu,  to  cut,  meaning  literally  dis- 
section. 

The  science  of  anatomy  comprises  the  study  of  the 
body  as  a  whole  and  the  relations  of  its  various  organs. 
It  is  divided  into  the  following  branches:  osteology,  the 
anatomy  of  the  bones;  syndesmology,  that  of  the  joints; 
myology,  that  of  the  muscles;  angiology,  that  of  the 
vessels;  neurology,  that  of  the  nerves;  splanchnology,  that 
of  the  internal  viscera;  adenology,  that  of  the  glands; 
dermatology,  that  of  the  skin;  genesiology,  that  of  the 
generative  organs. 


CHAPTER    I 

OSTEOLOGY 

WB  shall  first  consider  the  framework  (or  osseous 
system)  that  supports  the  body.  This  is  known  as  "the 
skeleton"  (from  the  Greek  (txsAstou,  a  dried  body),  and 
gives  attachment  to  the  muscles  and  forms  a  protection 
to  the  internal  organs. 

Bone. — Bone  is  the  hardest  structure  in  the  body; 
it  possesses  also  a  certain  degree  of  toughness  and  elas- 


Lacuna 
Canaliculi 


Fig.  I. — Portion  of  a  transversely  ground  disk  from  the  shaft  of  a  human 
femur;  X  400  (Bohm  and  Davidoff). 


ticity.  Its  color,  in  a  fresh  state,  is  of  a  pinkish  white. 
On  examination  it  will  be  found  to  be  composed  of  two 
kinds  of  tissues,  one  dense  and  compact,  like  ivory,  the 
other  made  ap  of  slender  fibers  (lamellcB)  arranged  in  the 
form  of  lattice  work,  and  called  cancellated  tissue.  The 
former  is  always  external,  and  the  latter  internal.  These 
combinations  vary  in  different  parts  of  the  body.     In 

13 


H 


ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 


portions  of  bone  subject  to  great  force  the  tissues  are 
more  compact,  while  the  parts  that  are  not  exposed  to 
severe  strain  are  provided  with  can- 
cellous tissue.  Bone  tissue  contains 
longitudinal  canals  that  communicate 
with  one  another,  and  are  called 
Haversian  canals.  They  convey  blood- 
vessels for  the  nutrition  of  the  bone. 

All  bones  are  covered  with  a  dense 
fibrous  vascular  membrane,  the  peri- 
osteum. The  medullary  and  cancel- 
lous cavities  of  bone  are  lined  with  a 
delicate  membrane,  the  endosteum 
containing  bone-forming  cells.  In 
their  normal  state  bones  have  but  little 
sensibility;  but  when  in  a  state  of  in- 
flammation they  are  extremely  sensi- 
tive and  painful. 

Chemic   analysis   shows   that  bone 
consists    of    organic     and     inorganic 
matter;   the  organic  is  called  animal, 
the  inorganic,  earthy  material;  these 
are  intimately  combined;  the  animal 
matter  furnishes  elasticity  and  tough- 
ness, the  earthy,  hardness  and  solidity. 
How  can  we  separate  the  two  kinds 
of   tissues   to  prove  that  this  is  the 
case?      This   is   done    by   steeping   a 
portion  of   bone    in   dilute   nitric   or 
hydrochloric   acid:    in    this   way   the 
earthy  material  is  taken  up,  leaving 
the  animal  or    organic    material    be- 
hind, so  that  the  bone  can  be  twisted  into  any  shape, 
thus   demonstrating  its  elasticity  and   toughness.     The 
presence   of  earthy  material  may  be   demonstrated  by 


Fig.  2. — Bone  tied  in 
knot  (Raymond). 


OSTEOLOGY  IS 

subjecting  the  bone  to  strong  heat  in  an  open  fire 
where  the  air  can  have  free  access,  until  all  the  organic 
material  is  consumed,  when  the  earthy  parts  will  be 
found  to  be  brittle,  preserving  the  original  shape  of  the 
bone. 

The  organic  constituents  of  bone  make  up  one-third, 
or  33.3  per  cent.,  of  the  whole;  the  inorganic  matter,  two- 
thirds,  or  66.7  per  cent.  For  the  convenience  of  the 
nurse  we  append  the  following  table  of  analysis  by  Berze- 
lius  (from  Wilson)  : 

f  Cartilage 32-17 

Organic  matter:         |  Blood-vessels 1.13 

r  Phosphate  of  lime 5 1 -04 

Carbonate  of  lime II  .30 

Inorganic  or  earthy  >   jri^^^ide  of  calcium 2.00 

"^^"^^=                        Phosphate  of  magnesia 1. 1 6 

[  Soda  and  chlorid  of  sodium  .    .    .  i-20 

ICX).CX) 

Some  difference  exists  in  the  proportion  of  the  two 
constituents  of  bone  at  different  periods  of  life.  Thus 
in  a  child  the  animal  matter  predominates,  whereas  in 
the  aged  the  bones  contain  a  larger  proportion  of  earthy 
matter,  the  animal  matter  being  deficient  in  quantity  and 
of  impaired  quality.  Hence  in  children  it  is  not  uncom- 
mon to  find,  after  an  injury,  that  the  bones  become  bent 
or  partially  broken — a  condition  known  as  greenstick 
fracture — whereas  in  old  persons  the  bones  are  more  brittle 
and  fracture  thus  takes  place  more  readily.  Many  of 
the  diseases,  also,  to  which  bones  are  liable  are  due  to  a 
disproportion  between  the  two  constituents  of  bone. 
Thus  in  the  disease  known  as  rickets,  so  common  among 
children  of  the  poor,  the  bones  become  bent  or  curved, 
either  from  the  superincumbent  weight  of  the  body  or 
under  the  action  of  certain  muscles.  This  is  due  to  some 
defect  of  nutrition  by  which  bones  are  deprived  of  their 


1 6        ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

normal  proportion  of  earthy  matter,  whereas  the  animal 
matter  is  of  unhealthy  quality. 

Cartilage  is  a  non-vascular  structure  which  is  found 
in  various  parts  of  the  body — in  adult  life  chiefly  in  the 
joints,  in  the  parietes  of  the  thorax,  and  in  various  tubes, 
such  as  air-passages,  nostrils,  and  ears,  which  are  to  be 
kept  permanently  open.  In  the  fetus,  at  an  early  period, 
the  greater  part  of  the  skeleton  is  cartilaginous.  As  this 
fetal  cartilage  is  afterward  replaced  by  bones,  it  is  called 
"temporary,"  in  contradistinction  to  that  which  remains 
unossified  during  the  whole  of  life,  and  which  is  called 
"permanent."  The  first  forms  the  original  framework 
of  the  skeleton,  and  becomes  ossified.  Permanent  car- 
tilage is  not  prone  to  ossification. 

Cartilages  are  classified,  according  to  their  function  and 
position,  into  articular,  interarticular,  costal,  and  mem- 
braniform.  Cartilage  is  divided,  as  to  its  minute  struc- 
ture, into  true  or  hyaline  cartilage,  fibrous  or  fibrocarti- 
lage,  and  yellow,  elastic,  or  reticular  cartilage. 

Articular  cartilage  forms  a  thin  layer  upon  the 
joint-surfaces  of  the  bones,  and  its  elasticity  enables  it 
to  break  the  force  of  any  concussion,  while  the  smoothness 
affords  ease  and  freedom  of  movement.  It  varies  in 
thickness  according  to  the  shape  of  the  bone  on  which  it 
lies.  A  cartilage  derives  its  nutriment  partly  from  the 
vessels  of  the  neighboring  synovial  membrane  as  well  as 
from  the  bones  upon  which  they  are  implanted. 

Marrow.— The  marrow  is  a  complex  tissue  which 
fills  up  the  cylindric  cavity  in  the  shafts  of  the  long  bones; 
it  also  occupies  the  spaces  of  the  cancellous  tissue  and  ex- 
tends into  the  larger  bony  canals  (Haversian  canals) 
which  contain  the  blood-vessels.  It  is  of  two  colors, 
yellow  and  red;  the  former  is  found  in  the  long  bones  of 
the  adult,  and  is  composed  of  fat  96  per  cent.,  areolar 
tissue  and  vessels  i  per  cent.,  fluid  3  per  cent.,  with  ex- 


OSTEOLOGY  1/ 

tractive  matter.  In  the  flat  and  short  bones,  in  the  articu- 
lar ends  of  long  bones,  in  the  bodies  of  the  vertebra,  in 
the  cranial  diploe,  and  in  the  sternum  and  ribs  it  is  of 
red  color,  and  contains  75  per  cent,  water,  25  per  cent,  of 
solid  matter,  consisting  of  albumin,  fibrin,  extractive  mat- 
ter, salts,  and  a  mere  trace  of  fat.  Marrow  possesses 
five  kinds  of  cells :  fat  cells,  marrow  cells  proper,  resem- 
bling leukocytes,  nucleated  red  cells,  cells  containing  red 
corpuscles,  and  giant  cells. 

Vessels  of  Bone. — The  blood-vessels  of  bone  are 
very  numerous.  Those  of  the  compact  tissue  are  de- 
rived from  a  close  and  dense  network  of  vessels  ramifying 
in  the  periosteum.  From  this  membrane  vessels  pass  into 
the  minute  orifices  in  the  compact  tissue,  running  through 
the  canals  which  traverse  its  substance.  The  cancellous 
tissue  is  supplied  in  a  similar  way  with  a  less  numerous  set 
of  larger  vessels.  In  the  long  bones  numerous  apertures 
may  be  seen  at  the  ends  near  the  articular  surfaces,  which 
give  passage  to  the  vessels  referred  to;  but  the  most  nu- 
merous and  largest  apertures  are  for  the  veins  of  the  can- 
cellous tissue,  which  run  separately  from  the  arteries. 
The  medullary  tissue  of  all  long  bones  receive  a  good-sized 
artery  (the  medullary  artery),  which  obliquely  pene- 
trates the  compact  tissue  at  the  nutrient  foramen,  after 
which  it  divides  into  two  main  branches,  one  ascending, 
the  other  descending,  in  the  medullary  canal;  the  veins 
chiefly  emerge  through  numerous  openings  near  the  articu- 
lar ends  of  the  bones,  and  form  the  nutrient  foramen. 
Nerves  are  distributed  freely  to  the  periosteum,  and  ac- 
company the  nutrient  arteries  into  the  interior  of  the 
bone. 

Haversian    Canals. — The     Haversian     canals     run 

parallel  with  the  longtiudinal  axis  of  the  bone  for  a  short 

distance,   and  then  branch   off  and  communicate   with 

others.      As  seen  in  cross-section  in  Fig.  i  they  appear 

2 


1 8        ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

as  round  or  oval  holes,  which  vary  in  diameter  from  2^^^ 
to  -5^Q  inch.  Each  canal,  as  a  rule,  contains  two  blood- 
vessels, a  small  artery,  and  vein;  the  larger  ones  also  con- 
tain a  small  quantity  of  connective  tissue  as  well  as  bone 
cells.  The  canals  near  the  surface  open  upon  it  by  minute 
orifices,  and  those  near  the  medullary  cavity  open  in  the 
same  way  into  the  spaces,  so  that  the  whole  of  the 
bone  is  permeated  by  a  system  of  blood-vessels  running 
through  the  bony  canals  in  the  center  of  the  Haversian 
system. 

Periosteum. — The  periosteum  is  a  fibrous  vascular 
membrane  which  adheres  to  the  surface  of  the  bones  in 
nearly  every  part,  except  their  cartilaginous  extremities. 
Where  strong  tendons  or  ligaments  are  attached  to  the 
bone,  the  periosteum  is  incorporated  with  them.  It  is 
composed  of  two  layers  closely  united  together.  In 
young  bones  the  periosteum  is  thick  and  very  vascular,  and 
is  intimately  connected  at  either  end  of  the  bone  with  the 
epiphyseal  cartilages,  but  less  closely  with  the  shaft,  from 
which  it  is  separated  by  a  layer  of  soft  blastema,  containing 
a  number  of  granular  corpuscles  or  "osteoblasts,"  in 
which  ossification  proceeds  on  the  exterior  of  the  young 
bone.  Later  in  life  the  periosteum  is  thinner,  less  vascu- 
lar, and  the  osteoblasts  have  become  converted  into  a 
connective-tissue  layer,  which  is  separated  from  the  rest 
of  the  periosteum  in  many  places  by  cleft-like  spaces, 
which  serve  as  a  nidus  for  the  ramification  of  the  vessels 
previous  to  their  distribution  in  the  bone;  hence  the 
liability  of  bone  to  exfoliation  or  necrosis  when  denuded 
of  this  membrane  by  injury  or  disease.  Nerves  and 
lymphatics  generally  accompany  the  arteries  in  the  peri- 
osteum. 

Endosteum. — The  endosteum  is  a  delicate  connective- 
tissue  membrane  lining  the  medullary  and  cancellous 
cavities   of   the   bone   which   contains   numerous   bone- 


OSTEOLOGY  1 9 

forming  cells.  Its  function  is  the  same  as  that  of  the 
periosteum. 

The  Development  of  Bone. — It  is  customary  to 
describe  three  varieties  of  bone  development.  These 
are:  'Tntracartilaginous,  intramembranous,  and  subperi- 
osteal." It  should  be  borre  in  mind,  however,  that  the 
essential  nature  of  the  process  is  the  same  in  all.  The 
two  latter  are  considered  under  one  head. 

At  an  early  period  of  life  most  of  the  long  and  irregular- 
shaped  bones  in  the  body  consist  of  masses  of  hyaline 
cartilage,  which  present,  in  a  general  way,  the  shape  of  the 
future  bone.  The  transformation  of  these  cartilage  masses 
into  bone  is  intracartilaginous  ossification.  This  is  al- 
ways associated  with  a  certain  amount  of  subperiosteal 
ossification.  The  bones  of  the  vertex  of  the  skull  and 
those  of  the  face,  with  few  exceptions,  are  formed  in  mem- 
brane; the  base  of  the  skull,  the  body,  and  the  limbs  are 
formed  in  cartilage.  In  the  former  the  bone-forming 
cells  (osteoblasts)  arrange  themselves  along  the  thick 
bundles  of  fibrous  tissue  which  radiate  from  the  center 
of  the  future  bone;  by  the  deposit  of  lime-salts  in  these 
osteoblasts  bone-tissue  grows  out  in  needle-like  rays  to- 
ward the  circumference.  A  deposit  of  bone  begins  at  one 
spot  in  the  cartilage  and  is  termed  the  primary  center. 
The  shaft  is  formed  from  this.  Just  before  ossification 
commences  the  cartilage  cells  enlarge  and  arrange  them- 
selves in  rows.  Lime-salts  are  deposited  in  the  matrix 
between  the  rows,  forming  columns  which  enclose  oblong 
spaces — the  primary  areolae — containing  cartilage  cells. 
Ossification  proper  now  commences  by  the  ingrowth  from 
the  periosteum  of  buds  of  young  connective  tissue,  covered 
with  bone-forming  cells,  which,  after  causing  absorption 
of  the  cartilage,  become  converted  into  bone. 


20        ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

(XASSIHCATION    OF   BONES 

The  bones  of  the  body  are  divided  into  four  groups: 
long,  short,  flat,  and  irregular.  These  go  to  make  up  the 
frame  that  protects  the  internal  organs,  and  provides 
attachment  for  the  several  soft  parts. 

The  long  bones  are  those  that  make  up  the  extremi- 
ties; the  short  bones  are  those  of  the  hands  and  feet;  the 
flat  bones  are  those  of  the  shoulder-blades,  pelvis, 
skull,  etc.;  the  irregular  bones  are  those  of  the  spine, 
as  well  as  the  ethmoid,  the  temporal,  etc. 

What  have  we  to  say  about  the  surfaces  oj  hones?  If 
you  examine  a  bone,  you  will  notice  that  it  has  certain 
eminences  and  depressions ;  these  have  technical  names, 
and  it  should  be  the  aim  of  the  nurse  to  become  acquainted 
with  each,  so  that  she  will  be  able  to  describe  a  part  con- 
cerned in  an  injury  in  a  practical  manner.  These  bony 
eminences  and  depressions  are  of  two  kinds :  articular  and 
non-articular. 

Examples  of  articular  eminences  are  found  in  the  head 
of  the  arm  bone  {humerus)  and  thigh  bone  {femur).  As 
examples  of  articular  depressions  may  be  mentioned  the 
glenoid  cavity  of  the  scapula  (shoulder-joint)  and  the 
acetabulum,  the  cavity  with  which  the  thigh  bone  ar- 
ticulates with  the  pelvis. 

Non-articular  eminences  are  distinguished  by  their 
form;  for  example,  a  broad,  rough,  uneven  part  of  a  bone 
is  called  a  tuberosity;  a  small,  rough  prominence,  a  tubercle; 
a  sharp,  slender,  pointed  eminence,  a  spine;  a  narrow, 
rough  elevation,  a  ridge  or  a  line.  The  non-articular 
eminences  and  depressions  serve  to  form  a  larger  field 
for  muscular  attachments,  and  are  greater  in  persons  who 
are  well  developed  from  exercise. 

Non-articular  depressions  vary  in  form,  and  are  known 
as  fossae,  grooves,  furrows,  fissures,  notches,  etc. 


OSTECLOGY. 


21 


PARIET/a 
TEMPORAL 


Fig.  3. — The  human  skeleton. 


22        ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

The  entire  skeleton  of  the  adult  is  made  up  of  200  dis- 
tinct bones.  These  are  divided,  according  to  Gray,  as 
follows : 

Cranium 8 

Spine  or  vertebral  column  (including  sacrum  and  coccyx)  .     26 

Face 14 

Sternum,  ribs,  os  hyoides 26 

Upper  extremities 64 

Lower  extremities 62 

200 

This  classification  includes  the  patellae,  but  not  the 
smaller  sesamoid  bones  nor  the  small  bones  of  the  ear. 
The  sesamoid  bones  are  found  in  the  substance  of  the 
tendons,  especially  of  the  great  toe.  Wormian  bones  are 
found  in  the  cranial  sutures  of  childhood;  they  are  irregu- 
lar fragments,  developed  from  supplementary  centers, 
ultimately  closing  the  fontanel. 

THE   SPINAL  COLUMN 

The  spine  is  a  flexible  column,  formed  of  a  series  of 
bones  called  vertebrae.  These  33  bones  are  divided  into 
five  regions,  named,  according  to  their  location,  as  fol- 
lows :  The  cervical,  consisting  of  7  bones ;  dorsal,  1 2  bones ; 
lumbar,  5  bones;  sacral,  5  bones;  coccygeal,  4  bones.  At 
a  period  of  life  varying  between  the  ages  of  twenty-five 
and  thirty  years  the  bones  in  the  sacral  and  coccygeal 
regions  become  united  and  form  2  bones. 

The  vertebrae  vary  in  size  and  in  shape.  They  are 
placed  one  upon  the  other,  thus  forming  a  support  for  the 
head  and  trunk.  Each  vertebra  is  divided  into  two  parts, 
the  anterior  forming  the  body,  the  posterior,  the  arch; 
the  arch  is  formed  by  2  pedicles  and  2  laminae,  supporting 
7  processes — viz.,  4  articular,  2  transverse,  and  i  spinous 
process.     The  functions  of  the  processes  are  to  give  at- 


OSTEOLOGY 


23 


tachment  to  the  various  muscles,  to  act  as  levers  to  move 
the  spine  in  different  directions,  and 
to  articulate  with  neighboring  bones. 
The  arches  of  the  vertebrae  form  a 
canal  for  the  passage  of  the  spinal 
cord ;  between  each  pair  of  vertebrae 
apertures  exist  through  which  the 
spinal   nerves  pass  from  the  cord. 

The  alias  supports  the  head;  the 
axis  articulates  with  the  atlas;  each 
of  the  12  dorsal  segments  articu- 
lates with  the  ribs  of  each  side ;  the 
sacrum  articulates  with  the  two 
hip-bones  {pssa  innominatd)  and 
the  last  lumbar;  the  coccyx  articu- 
lates with  the  last  sacral.  The 
average  length  of  the  spine  is  about 
2  feet  4  inches.  It  presents  several 
curves  that  correspond  to  the  dif- 


FlG.  4.— The  figures 
indicate  the  relations  of 
the  vertebral  bodies  and 
spines  to  the  correspond- 
ing spinal  segment?  of 
the  cord  (Church). 


Fig.  S. — A  type-vertebra:  i,  body;  2,  ped- 
icle;  3,  lamina;  4,  spinal  foramen;  5,  spinous 
process;  6,  transverse  process;  7,  articular 
process  (Leidy), 


ferent  segments  of  the   column,  viz.:  the  cervical  with 


24        ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

the  neck;  the  dorsal  with  the  chest  or  thorax;  the  lumbar 
with  the  abdomen;   the  sacral  with  the  pelvis. 

The  nurse  should  carefully  study  the  several  illustra- 
tions in  order  fully  to  understand  the  shape  of  the  seg- 
ments that  form  the  spine,  as  each  has  important  con- 
nections. 

The  physician  will  frequently  direct  that  a  nurse  apply 

a  blister  or  a  hot  application  to  one  of  the  several  regions, 

and  she  must,  therefore,  be  well  informed  in  this  respect 

in  order  that  his  directions  may  be  intelligently  carried 

out. 

THE    SKULL 

The  skull  is  considered  as  an  expansion  of  the  vertebral 
column.  It  is  the  bony  framework  of  the  head,  and  con- 
tains a  cavity  for  the  reception  of  the  brain,  vessels,  nerves, 
and  membranes.  The  bones  of  the  skull  are  divided  into 
two  classes — the  cranial  consisting  of  8  bones,  and  the 
facial  consisting  of  14  bones.  The  nurse  should  be  famil- 
iar with  the  names  and  location  of  these  bones,  in  order 
that  she  may  be  able  to  describe  to  the  physician  the  exact 
location  of  pain,  and,  in  surgical  cases,  to  make  accurate 
records  during  the  physician's  absence.  The  following 
bones  enter  into  the  formation  of  the  skull : 

r  I  occipital. 


Bones  of  the  cranium  : 


Bones  of  the  face  : 


2  parietal. 
I  frontal. 

2  temporal. 

I  sphenoid. 

.  I  ethmoid. 

r  2  nasal. 

2  superior  maxillary. 
2  lacrimal. 

2  malar. 

2  palate. 

2  inferior  turbinated. 

I  vomer. 

[  I  inferior  maxillary. 

OSTEOLOGY 


25 


The  occipital  bone  forms  the  back  and  base  of  the 
cranium  and  articulates  with  the  atlas.  It  contains  the 
foramen  magnum,  an  opening  for  the  exit  of  the  spinal 
cord. 


Fig.  6. — Front  view  of  the  skull  (Sobotta). 


The  parietal  bones  form  the  sides  and  roof  of  the 
cranium.  The  frontal  bone  forms  the  forehead,  and 
is  often  the  seat  of  pain  in  diseases  of  the  head  and  eye, 
as  it  forms  part  of  the  bony  cavit}'^  that  receives  the  eye. 
It  also  unites  with  the  two  parietal  bones,  thus  forming 
the  space  in  the  center  of  the  head  called  the  anterior 


26        ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

fontanel,  and  generally  known    among   mothers  as  the 


Fig.  7. — Infant's  skull :  anterior  fontanel  above ;  posterior  fontanel  below 

(J.  P.  C.  Griffith). 


ruettno-Jtfftsfoiet 


Syftntat 

QhnoielTesit* 
JfiifmieiH  Jl^r^in 
9i/mpunic  Jfinji 

CaroiidCanal- 


^„-.,,,_        Portion 

WZoeeipit«t?Givovf> 

^     „  _^  inning  A^asfeiJPiVeea, 
Opening  fat  jS'fy/ei J  Process 
^  -  yl^as/o<  J  foramen 


Fig.  8. — Temporal  bone  of  infant ;  lower  outer  surface,  showing  squamous, 
tympanic,  and  petromastoid  segments  (Randall). 


"soft  Spot";  this  is  found  in  the  infant  at  birth,  but  ulti- 
mately becomes  obliterated. 


OSTEOLOGY 


27 


The  temporal  bones  are  situated  at  the  side  of  the 
head,  and  contain  the  organs  of  hearing.  A  knowledge 
of  the  location  of  these  bones  is  important,  as  they  are 
frequently  the  seat  of  disease;  they  should,  therefore,  be 
well  considered  by  the  nurse.  In  children,  especially 
after  scarlet  fever,  these  bones  often  become  diseased  and 
require  the  attention  of  the  nurse ;  such  disease  may  result 
in  chronic  discharges. 

The  sphenoid  and  ethmoid  bones  are  situated  at  the 
base  of  the  skull,  and  form  the  connection  between  all  the 


Horizontal 
plate  of 
ethmoid. 


Rostrum  of 
sphenoid. 


Vomer. 


Palatal. 


Frontal. 

Nasal. 

Perpendicular 
plate  of 
ethmotd. 

Carttlat^e  of 
septum. 

Lower  lateral 
cartilage. 

Superior 
maxillary. 


Fig.  9. — Cartilage  and  bones  of  the  septum  of  the  nose  (Ingals). 

bones  of  the  cranium  and  face,  with  the  exception  of  the 
inferior  maxillary. 

The  two  nasal  bones  form  the  bridge  of  the  nose; 
the  vomer,  the  back  part  of  the  septum. 

The  superior  maxillary  bones  are  the  largest  bones 
of  the  face,  excepting  the  inferior  maxillary,  and  con- 
tain, sockets  for  the  reception  of  the  upper  teeth.  They 
aid  in  forming  three  cavities  in  the  head — the  roof  of  the 
mouth,  the  floor  and  outer  wall  of  the  nose,  and  the  floor 


28        ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

of  the  orbit,  which  receives  the  eye.  There  is  also  within 
each  bone  a  cavity,  called  the  antrum  of  Highmore,  which 
in  some  subjects  becomes  the  seat  of  a  serious  inflamma- 
tion; this  cavity  is  situated  at  about  the  middle  of  the 
bone,  and  renders  the  bone  lighter. 


Sinciput 


QCCLput 


Fig.  io. — Side  view  of  the  skull  (Sobotta). 


The  malar  bones  go  to  make  up  the  prominence  of 
the  cheek,  and  assist  in  forming  the  cavity  for  the  recep- 
tion of  the  eye.  The  lower  part  of  the  posterior  border 
articulates  with  the  temporal  bone  to  form  the  zygomatic 
arch. 

The  palate  bones  are  situated  at  the  back  part  of 
the  nose,  helping  to  form  the  nasal,   oral,  and  orbital 


OSTEOLOGY 


29 


cavities.  The  inferior  turbinated  bones  are  found  on 
the  outer  wall  of  the  nasal  cavity.  The  vomer  forms  the 
central  septum  of  the  nose. 


p/-/. 


Fig.  II. — Inferior  maxillary  bone,  outer  surface,  side  view  (Gray). 

The  orbit  is  the  cavity  for  the  reception  of  the  eye,  and 
is  formed  by  seven  bones. 

Major  cornu. 


Minor  cornu.  - 


Body. 
Fig.  12. — The  hyoid  bone,  viewed  from  above  (Toldt). 

The   inferior  maxillary  bone  consists   of   a   body, 
with  two  rami,  which  are  surmounted  on  either  side  by  a 


30        ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

thin  triangular  coronoid  process  in  front,  and  an  articular 
condyloid  process  posteriorly.  The  constricted  portion 
beneath  the  condyle  is  termed  the  neck  oj  the  condyle. 
The  depression  separating  these  two  processes  is  called  the 
sigmoid  notch,  and  is  crossed  by  the  mes6l!8teric  vessels  and 
nerve.  This  bone  is  one  with  whose  location  the  nurse 
should  be  familiar,  as  it  is  subject  to  many  conditions  that 
require  surgical  attention.  It  is  most  liable  to  fracture, 
and  frequently  becomes  dislocated  as  the  result  of  a  very 
light  blow.  It  contains  sockets  for  the  reception  of  the 
lower  teeth. 

The  hyoid  bone,  sometimes  called  the  lingual  bone, 
is  a  bony  arch  shaped  like  a  horseshoe.  It  supports  the 
tongue  and  gives  attachment  to  numerous  muscles. 

THORAX   AND    PELVIS 

The  thorax  is  that  part  of  the  body  that  goes  to  make 
up  the  chest.  It  forms  a  protection  for  the  organs  of 
respiration  and  circulation,  inclosing  one  of  the  cavities 
of  the  trunk,  known  as  the  thoracic  cavity.  The  thorax 
is  conic  in  form,  and  its  osseocartilaginous  framework  is 
formed  by  the  thoracic  vertebral  bodies  behind,  the  ribs 
laterally,  and  the  costal  cartilages  and  sternum  in  front; 
its  base  is  formed  by  the  diaphragm.  Through  its  apex 
pass  the  great  cervical  vessels,  the  pneumogastric,  phrenic 
and  sympathetic  nerves,  the  trachea,  esophagus,  thoracic 
duct,  and  apices  of  the  lungs  covered  by  pleura. 

The  sternum,  popularly  known  as  the  breast-bone,  is 
divided  into  three  parts — the  manubrium,  or  handle;  the 
gladiolus,  or  sword;  and  the  ensiform,  or  xiphoid  appendix. 
The  manubrium  articulates  with  the  clavicle  and  first  rib ; 
the  gladiolus  with  cartilages  of  part  of  the  second,  all  of 
the  third  to  sixth,  and  part  of  the  seventh  ribs  on  each  side ; 
the  ensiform  articulates  with  part  of  the  seventh  costal 
cartilage  and  cartilages  of  the  false  ribs. 


OSTEOLOGY 


31 


There  are  twelve  ribs  on  each  side ;  these  are  of  different 
shapes,  conforming  to  their  location.  They  serve  for 
the  attachment  of  the  several  muscles  of  the  chest  and 
abdomen.  They  are  all  connected  behind  with  the  dorsal 
vertebrae  of  the  spine,  and  the  first  seven  are  connected 
with  the  sternum  by  the  costal  cartilages;  these  are  called 
true  ribs.     The  remaining  five  pairs  are  called  false  ribs; 


Circumference  of  apex  of  thorax. 


Eleventh  rib. 


Circumference  of  base. 
Fig.  13. — Thorax  (anterior  view)  (Ingals). 


of  these,  the  first  three  are  attached  in  front  to  the  costal 
cartilages,  and  are  termed  the  vertebrocostal,  while  the 
remaining  two,  being  unattached  in  front,  are  known  as 
vertebral  or  floating  ribs. 

The  convexity  of  each  curved  rib  is  turned  outward,  so 
as  to  give  roundness  to  the  side  of  the  chest  and  increase 
the  dimensions  of   its    cavity  when  the  ribs  are  raised; 


32 


ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 


each  slopes  downward  from  its  vertebral  attachment,  so 
that  its  sternal  end  is  considerably  lower  than  its  dorsal. 

The  ribs  are  classed  as  irregular  bones.  The  spaces 
between  the  ribs  are  called  intercostal  spaces,  a  fact  to  be 
remembered  by  the  nurse  when  describing  the  location  of 
pain  or  of  an  eruption. 

Below  the  diaphragm,  and  above  the  pelvic  bones,  we 
have  the  second  cavity  of  the  trunk,  called  the  abdominal 


,'''^ 


Fig.  14. — First  dorsal  vertebra 
and  rib  (Reichert). 


Fig.  15. — Sixth  dorsal  vertebra  and  rib 
(Reichert). 


cavity;  this  contains  the  organs  of  digestion,  which  will  be 
considered  when  discussing  visceral  anatomy. 

The  pelvis  is  a  basin-like  cavity,  formed  by  the  sa- 
crum, coccyx,  and  two  ossa  innominata.  It  is  divided  into 
two  parts  by  the  brim  of  the  pelvis  or  pelvic  inlet.  The 
portion  of  the  pelvic  cavity  above  the  pelvic  brim  is  a 
part  of  the  abdominal  cavity;  the  portion  below  is  the  true 


OSTEOLOGY 


33 


pelvic  cavity.  The  latter  contains  the  organs  of  genera- 
tion, the  rectum,  the  bladder,  the  ureters,  and  the 
blood-vessels.  The  peVdic  outlet  is  formed  by  the  pubic 
arch  in  front  and  the  coccyx  and  sacrosciatic  ligaments  be- 
hind; the  lateral  boundaries  are  formed  by  the  tuberosities 
of  the  ischia.  The  transverse  diameter  of  the  pelvic  out- 
let averages  3^  inches  in  the  male  and  \\  inches  in  the 
female. 


Fig.  16. — Front  view  of  the  pelvis,  with  its  ligaments  :  i,  innominate 
bone;  2,  crest  of  ilium;  3,  sacrum;  4,  pubes ;  5,  tuberosity  of  ischium;  6, 
anterior  superior  spine  of  ilium;  «,  anterior  sacroiliac  ligament;  <5,  ilio- 
femoral ligament;  c,  obturator  membrane;  d,  symphysis  pubis;  e,  sacro- 
sciatic ligament  (Dorland). 


The  sacrum  is  a  curved,  triangular  bone,  situated  be- 
tween the  two  ossa  innominata,  and  forming,  with  the 
coccyx,  the  posterior  part  of  the  pelvis.  It  is  formed  of 
five  vertebrae,  which,  after  the  twenty-fifth  year,  become 
united  as  one  bone.  The  cocc3rx  consists  of  four  bones 
articulating  with  the  sacrum,  and  is  subject  to  fractures 
and  necrosis,  conditions  that  require  surgical  operations 
for  their  cure.  Injuries  to  this  bone  sometimes  occur  dur- 
3 


34        ANATOMY  AND   PHYSIOLOGY  FOR  NURSES      ' 

ing  labor,  especially  in  instrumental  cases,  from  the 
pressure  of  the  child's  head  in  its  passage  through  the 
outlet  of  the  pelvis. 

The  ossa  innominata,  or  nameless  bones,  form  the  sides 
and  anterior  wall  of  the  pelvic  cavity.  They  are  divided 
into  three  parts — the  ilium,  the  ischium,  and  the  pubes; 
in  adults  these  become  consolidated  and  form  one  bone. 
At  the  junction  of  the  three  parts  is  found  the  acetabulum, 
which  articulates  with  the  head  of  the  femur.  The  up- 
per border  of  the  bone  is  called  the  crest  of  the  ilium;  the 
lower,  the  ischium;  and  the  anterior,  the  pubes.  The 
anterior  extremity  of  the  iliac  crest  is  called  the  anterior 
superior  spine  of  the  ilium;  that  portion  of  the  ischium 
upon  which  we  sit  is  the  tuberosity;  the  junction  of  the 
pubic  bones  is  known  as  the  symphysis.  These  are  im- 
portant landmarks. 

THE   BONES   OF   THE    UPPER   EXTREMITY 

The  bones  of  the  upper  extremity  are  the  clavicle  and 
scapula  (comprising  the  shoulder  girdle),  the  humerus, 
the  radius  and  ulna,  the  carpal  bones,  the  metacarpal 
bones,  and  the  phalanges. 

The  clavicle  or  collar-bone,  is  shaped  like  the  letter  fy 
and  articulates  with  the  sternum  and  the  scapula. 

It  has  a  wide  range  of  motion,  and  this,  together  with  its 
exposed  position  and  the  fact  that  it  is  the  only  bony  con- 
nection between  the  trunk  and  the  upper  extremity,  ex- 
plains why  the  clavicle  is  more  frequently  broken  than  any 
other  single  bone  in  the  body. 

The  scapula  or  shoulder-blade,  is  situated  on  the 
posterior  and  lateral  part  of  the  thorax,  overlying  the 
region  included  between  the  second  and  the  seventh  ribs. 
The  dorsal  surface  of  the  bone  is  traversed  by  an  elevated 
ridge — the  spine — the  outer  extremity  of  which  overhangs 
the  shoulder,  and  is  known  as  the  acromion.    Just  beneath 


OSTEOLOGY 


35 


Acromion. 
Greater  tuberosity: 


Humerus.' 


Outer  condyle. 
Head  of  radius. 


Ulna 

Radius. — 
Interosseous  space 


' Inner  condyle. 


Metacarpus. 


Phalini^es. 


Scapula. 


Carpus. 
Metacarpus. 


" "~— --;  Phalanges. 


Fig.  17, — Bones  of  the  upper  extremity  (Toldt). 


the  acromion  process  is  found  a  shallow  depression — the 
glenoid  cavity— which  articulates  with  the  head  of  the 


36        ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

humerus.      The  coracoid  process  (or  "crow's  beak")   is 
situated  to  the  inner  side  of  the  glenoid  cavity  and  gives 


Olecranon 


Tuberosity. 


Arterial  foramina. 


Radius. 


Interosseous  space.  - 


Greater  sigmoid 
cavity. 


Ulna. 


Fig.  i8. — Bones  of  the  right  forearm  in  a  position  of  supination  (Toldt). 


origin  to  a  portion  of  the  biceps  muscle.     The  scapula  is 
classified  as  a  flat  bone. 

From  the  standpoint  of  the  anatomist,  that  portion  of 
the  upper  extremity  between  the  shoulder  and  the  elbow 


OSTEOLOGY  3/ 

is  the  arm,  while  that  between  the  elbow  and  wrist  is  the 
forearm. 

The  humerus  is  the  long  bone  in  the  arm.  Its  upper 
extremity  presents  for  examination  a  rounded  head,  which 
articulates  with  the  glenoid  cavity  of  the  scapula,  and  two 
eminences,  the  greater  and  the  lesser  tuberosity.'  The  cir- 
cumference of  the  articular  surface  of  the  head  is  known  as 
the  anatomic  neck.  Since  the  constricted  portion  of  the 
bone  below  the  tuberosities  is  frequently  fractured,  it  is 
called  the  surgical  neck.  The  lower  expanded  extremity 
of  the  humerus  is  flattened  from  before  backward  to  form 
the  condyles.  The  internal  condyle  articulates  with  the 
ulna,  while  the  external  articulates  with  the  radius. 

The  ulna  is  the  inner  bone  of  the  forearm;  it  is  longer 
than  the  radius,  and  helps  to  form  the  elbow-joint,  but 
does  not  enter  into  the  formation  of  the  wrist-joint.  The 
upper  end  presents  a  curved  process,  called  the  olecranon, 
and  the  cavity  thus  formed  articulates  with  the  humerus, 
and  is  called  the  sigmoid  cavity. 

The  radius  is  the  outer  bone  of  the  forearm,  and  is 
shorter  than  the  ulna.  The  upper  rounded  head  helps 
to  form  the  elbow-joint ;  the  lower  end  articulates  with  the 
carpus  to  form  the  wrist-joint,  and  is  subject  to  many 
injuries,  the  most  common  of  which  is  that  known  as 
"Colics'  fracture."  Many  suits  for  malpractice  have 
been  instituted  as  the  result  of  this  injury,  the  physician 
often  being  held  responsible  for  bad  results  that  followed 
carelessness  on  the  part  of  the  patient. 

When  the  radius  and  ulna  are  parallel,  the  foramen  is 
said  to  be  supinated;  when  the  bones  are  crossed,  the 
forearm  is  pronated. 

THE    HAND 

The  bony  framework  of  the  hand  is  made  up  of  the 
carpus,  which  consists  of  eight  bones,  the  metacarpus, 


38        ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

consisting  of  five  bones,  and  the  fourteen  bones  termed 
the  phalanges.  The  bones  of  the  carpus,  together  with 
the  radius,  enter  into  the  formation  of  the  wrist-joint« 
The  bones  of  the  upper  row  are  the  scaphoid,  semilunar, 
cuneiform,  and  pisiform;  those  of  the  lower  row,  the 
trapezium,  trapezoid,  os  magnum,  and  unciform. 

The  metacarpus  forms  the  palm  of  the  hand.  The 
phalanges  form  the  fingers;  each  finger  is  made  up  of 
three  phalanges,  the  thumb,  of  two.     Although  classified 


Fig.  19. — Right  carpal  bones,  dorsal  surface:  S,  scaphoid;  L,  semilunar; 
C,  cuneiform  ;  P,  pisiform  ;  U,  unciform  ;  7,  os  magnum  ;  ^T,  trapezoid ;  T, 
trapezium  (Leidy). 

as  long  bones,  they  are  also  numbered  among  the  short 
bones  of  the  body.  Bach  bone  is  composed  of  a  base,  a 
shaft,  and  an  extremity.  '^  '-  ' 

THE   BONElS   C^  -"i^HE   LO^ER   EX'I'REMITY-'^  »     - 

The  lower  extremity  is  composed  of  the  thigh,  the  leg, 
and  the  foot. 

The  femur,  or  thigh-bone,  is  the  longest  bone  in  the 
body.  The  rounded  head  articulates  with  the  acetabulum 
of  the  OS  innominatum.     The  head  is  joined  to  the  shaft 


Innominate  hone 


Great  trochanter^ 


X 


^Lesser  trochanter. 


Femur. 


Outer  condyle. 
Outer  tuberosity, — \ 
Head. 


Tibia. 

Fibula. 
Interosseous  space. 


Inner  condyle. 

Patella. 

Inner  tuberosity. 


Crest. 


Outer  malleolus.  - 

Metatarsus..: 
Phalanges.  "^^[^ 


'Phalanges. 
Fig.  20. — Bones  of  the  lower  extremity  (Toldt). 


Inner  malleolus. 
•  Tarsus. 

■  Metatarsus. 


29 


40        ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

by  a  constricted  neck.  At  the  junction  of  neck  and  shaft 
are  found  the  greater  and  lesser  trochanters.  The  lower 
end  of  the  bone  is  expanded  to  form  two  large  condyles, 
which  articulate  with  the  tibia  and  the  patella.  It 
gives  attachment  to  the  strongest  muscles  of  the  body. 

The  leg  consists  of  two  bones — the  tibia  and  the 
fibula.  The  patella  is  a  sesamoid  bone  embedded  in  the 
tendon  of  the  quadriceps. 

The  tibia  is  the  large  bone  on  the  inner  side  of  the  leg. 
The  upper  portion  is  expanded  to  form  two  tuberosities 
which  articulate  with  the  condyles  of  the  femur  to  form 
the  knee-joint.      The  sharp  anterior  edge  of  the  bone 


a  b 

Fig.  21. — Right  patella:  a.  Anterior  surface  ;  b,  posterior  surface 

(Nancrede). 


is  called  the  crest  ("the  shin").  The  lower  end  of  the  tibia 
is  known  as  the  inner  malleolus,  and  articulates  with  the 
astragalus,  thus  aiding  in  the  formation  of  the  ankle- 
joint. 

The  fibula  is  the  long,  slender  bone  on  the  outer  side  of 
the  leg.  The  upper  end,  or  head,  articulates  by  a  flat  facet 
with  the  tibia  and  takes  no  part  in  forming  the  knee-joint. 
The  lower  end  of  the  bone  is  the  outer  malleolus  and  helps 
to  form  the  ankle-joint.  A  fracture  of  the  lower  fifth  of 
the  fibula  is  commonly  called  a  Potts'  fracture. 

The  patella,  or  knee-cap,  is  a  fiat,  triangular  bone 
that  helps  to  make  up  the  knee-joint.    The  lower  portion, 


OSTEOLOGY  4 1 

or  apex,  is  connected  with  the  tibia  by  the  tendo  patella. 
The  posterior  surface  of  the  bone  presents  two  facets 
which  articulate  with  the  condyles  of  the  femur.  The 
anterior  surface  is  separated  from  the  skin  by  a  bursa; 
when  this  bursa  is  enlarged  the  condition  is  known  as 
"house-maids'  knee." 

THE   FOOT 

The  foot  is  divided  into  the  tarsus,  which  consists  of 
7  bones,  the  metatarsus,  consisting  of  5  bones,  and  the 


Fig.  22. — Bones  of  the  right  foot,  dorsal  surface  :  i,  Astragalus ;  2,  head 
of  the  astragalus;  3,  os  calcis ;  4,  navicular  bone;  5,  internal  cuneiform; 
6,  middle  cuneiform  ;  7,  external  cuneiform  ;  8,  cuboid  ;  9,  metatarsal  bones; 
10,  II,  12,  13,  14,  phalangeal  bones  (Leidy). 


phalanges,  14  in  number,  making  a  total  of  26  bones. 
They  are  placed  in  two  rows.  The  uppermost  bone  of  the 
tarsus  is  called  the  astragalus  and  articulates  with  the 
tibia  and  fibula. 


42        ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

The  heel-bone  is  in  the  lower  posterior  part  of  the  foot, 
and  is  called  the  os  calcis.  It  is  classed  as  an  irregular 
bone.  The  5  metatarsal  bones  are  classed  with  the 
long  bones  and  articulate  with  the  tarsus. 

The  phalanges  of  the  foot  number  14,  just  as  in  the 
hand;  the  great  toe  is  made  up  of  two  phalanges,  the  other 
toes  having  three.  They  are  classed  as  long  bones,  and, 
from  their  location,  are  subject  to  many  injuries. 

THE   ARTICULATIONS 

The  various  bones  of  which  the  skeleton  is  made 
up  are  connected  at  different  parts  of  their  surfaces  to 
form  joints  or  articulations.     If  the  joint  be  immovable, 


Fig.  23. — Ligaments  of  the  shoulder:  a,  Superior  acromioclavicular 
ligament ;  b,  coraco-acromial  ligament ;  c,  coracohumeral  ligament;  d, 
transverse  ligament;  <?,  coracoclavicular  ligament;/  anterior  costosternal 
ligament ;  g,  interclavicular  ligament ;  h,  anterior  sternoclavicular  ligament ; 
J,  costoclavicular  ligament ;  j,  capsular  ligament. 

as  those  between  the  cranial  and  most  of  the  facial  bones, 
the  adjacent  surfaces  are  brought  into  close  approxima- 
tion with  an  intervening  thin  layer  of  fibrous  membrane — 
the  sutural  ligament;  in  certain  situations,  at  the  base  of 
the  skull,  a  thin  layer  of  cartilage  is  interposed. 

Where  slight  movement  combined  with  great  strength 
is  required,  as  in  the  joints  of  the  spine,  the  sacro-ihac. 


OSTEOLOGY 


43 


and  the  interpubic  articulations,  the  osseous  surfaces  are 
united  by  tough  and  elastic  fibrocartilage ;  but  in  the 
movable  joints  the  bones  forming  the  articulation  are 


Fig.  24. — Ligaments  of  the  knee-joint:  yi,  Anterior  aspect:  a,  Femur; 
b,  ligamentum  patellae ;  c,  internal  lateral  ligament ;  d,  external  lateral  liga- 
ment. B,  Posterior  aspect:  a,  Femur;  b,  posterior  ligament;  c,  internal 
lateral  ligament ;  d,  external  lateral  ligament ;  e,  posterior  ligament  of  pero- 
neotibial articulation  ;  /,  interosseous  ligament. 


Fig.  25. — Ligaments  of  the  wrist-joint:  A,  Anterior  aspect:  a,  Radius; 
b,  ulna ;  c,  anterior  radio-ulnar  ligament ;  d,  internal  lateral  ligament ;  e,  an- 
terior ligaments ;  f,  external  lateral  ligaments ;  g,  first  metacarpal  bone  ;  h, 
palmar  ligaments ;  i,  palmar  carpal  ligaments  ;  j,  capsular  ligament.  B, 
Dorsal  aspect :  a.  Ulna ;  b,  radius ;  c^  posterior  radio-ulnar  ligaments ;  d, 
posterior  ligament. 


generally  expanded  to  allow  greater  freedom  for  mutual 
connection.  These  bones  are  covered  by  an  elastic  struc- 
ture called  cartilage,  held  together  by  strong  bands  or 


^ 


44        ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

A 


Fig.  26. — Ligaments  of  the  foot:  A,  Dorsal  aspect:  a,  Astragalus;  b, 
calcaneo-astragaloid  ligaments;  c,  dorsal  ligaments  of  tarsus;  </,  tarsometa- 
tarsal ligaments ;  e,  transverse  ligaments,  B,  Plantar  aspect :  a,  Os  calcis ; 
b,  greater  calcaneocuboid  ligament ;  c,  deep  calcaneocuboid  ligament ;  d, 
inferior  tarsometatarsal  ligament ;  e,  tarsometatarsal  ligaments. 


Patella. 

Synovial  mem- 
brane, cavity  of. 
joint. 

Femur, 


Fig.  27. 


-Horizontal  frozen  section  of  the  knee-joint,  showing  lateral  extent 
of  synovial  membrane  (Professor  Dwight's  specimen). 


capsules  of  fibrous  tissue  called  ligaments,  and  lined  by 
a  membrane  (the  synovial  membrane)  that  secretes  a 
fluid  that  lubricates  the  various  parts  of  which  the  joint  is 


OSTEOLOGY  45 

formed.  The  structures  that  enter  into  the  formation  of 
a  joint  are  bone,  cartilage,  fibrocartilage,  Hgament,  and 
synovial  membrane. 

Bone  constitutes  the  fundamental  element  of  all  the 
joints.  Cartilage  is  a  firm,  opaque,  pearly-white,  or  bluish- 
white — in  some  varieties  yellow — highly  elastic,  flexible 
tissue,  possessed  of  considerable  cohesive  power.  It 
yields  readily  to  pressure,  and  resumes  its  shape  when  the 
force  is  removed.  The  synovial  membrane  will  be  con- 
sidered when  the  membranes  of  the  body  are  described. 

The  movable  joints  of  the  human  body  are  classified 
according  to  their  range  of  motion  as  follows : 


Uniaxial  joints: 
Biaxial  joints: 
Polyaxial  joints: 


{;: 


Hinge  joints. 
Pivot  joints. 

Condyloid  joints. 
Saddle  joints. 

Gliding  joints. 
Ball-and-socket  joints 


In  the  hinge  joint  the  motion  is  about  a  transverse  axis. 
Examples — the  ankle-joint  and  part  of  the  elbow-joint 
(the  articulation  between  the  humerus  and  the  ulna).  In 
the  pivot  joint  the  motion  is  about  a  longitudinal  axis. 
Examples — the  joint  between  the  atlas  and  the  axis  and 
part  of  the  elbow- joint  (the  articulation  between  the 
ulna  and  the  head  of  the  radius. 

In  the  condyloid  joint  the  two  axes  of  motion  are  placed 
at  right  angles  to  one  another,  but  both  pass  through  the 
same  bone.  Examples — the  wrist- joint  and  the  articula- 
tion between  the  atlas  and  the  occiput.  The  saddle  joint 
is  formed  by  the  approximation  of  two  saddle-shaped  sur- 
faces, the  axes  of  motion  being  at  right  angles  to  each 
other,  but  passing  through  different  bones.  Example — 
the  carpometacarpal  joint  of  the  thumb. 


46 


ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 


In  the  gliding  joints  a  spheric  head  moves  in  a  spheric 
socket,  but  the  articulating  surfaces  are  segments  of  such 
large  spheres  that  they  seem  to  be  almost  plane.  Example 
— the  joints  between  the  articular  surfaces  of  the  vertebrae. 
In  the  ball-and-socket  joints  the  articular  surfaces  are  more 
extensive  segments  of  smaller  spheres  and  the  capsular 
ligaments  are  more  roomy,  so  that  a  wide  range  of  motion 
is  possible.  Examples — the  shoulder- joint  and  the  hip- 
joint. 

TENDONS 

Tendons  are  white,  glistening,  fibrous  cords,  varying 
in  length  and  thickness.     They  are  round,   sometimes 


•  Tendon-cell. 
.  Tendon-fibers. 


Fig,  28. — Longitudinal  section  of  tendon  (X  270)  (Bohm  and  Davidoff). 


flattened,  of  considerable  strength,  but  slightly  elastic,  and 
almost  without  blood  or  nerve  supply.  They  serve  to 
connect  the  muscular  tissue  to  the  part  to  be  moved. 


OSTEOLOGY  47 

Aponeuroses  are  membranous  expansions  of  the  same 
tissue  and  serve  a  similar  purpose. 

Fasciae  are  fibrous  or  fibro-areolar  layers  investing 
the  soft  tissues.  The  superficial  fasciae  are  usually  fibro- 
areolar,  lie  beneath  the  skin,  and  are  loaded  with  fat; 
the  deep  fasciae  resemble  aponeuroses.  They  are  dense 
and  inelastic,  and  either  ensheath  muscles  or  serve  for 
their  attachment.  They  tend  to  preserve  the  part,  since 
partitions  descend  between  various  muscles  to  become 
attached  to  the  periosteum. 

ADIPOSE   TISSUE 

Adipose  tissue,  or  fat,  is  distributed  very  generally 
throughout  the  body.  It  has  a  copious  supply  of  blood- 
vessels and  lymphatics,  but  no  nerves  have  been  known 
to  terminate  in  it.  In  some  subjects  it  is  present  in  such 
abundance  about  the  internal  organs  as  to  interfere  with 
their  functions.  It  helps  to  maintain  bodily  heat,  and 
rounds  out  the  contour  of  the  body.  Its  presence  or 
absence  is  an  index  of  the  nutritive  and  assimilative  powers 
of  the  individual. 

REVIEW    QUESTIONS 

Define  the  term  Anatomy, 

Into  what  branches  is  it  divided? 

What  is  Osteology? 

What  is  bone,  and  what  is  its  composition? 

What  canals  are  there  in  the  bone? 

What  is  the  periosteum,  its  function? 

Have  the  bones  much  sensibility? 

State  the  chemic  analysis  of  bone. 

How  may  the  constituents  of  bone  be  demonstrated? 

Is  there  any  difference  in  their  proportions  at  different  ages? 

In  what  disease  is  there  a  disproportion  in  constituents? 

How  do  fractures  in  the  yOung  differ  from  fractures  in  the  aged? 

Give  the  reasons  for  this  difference. 

Into  how  many  classes  are  bones  divided?    Name  them. 


48         ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

Name  their  location. 

What  are  eminences? 

Give  an  example  of  same. 

What  are  depressions?     Give  an  example. 

How  many  bones  are  there  in  the  adult  skeleton? 

How  are  they  divided  as  to  number? 

What  are  sesamoid  bones? 

What  are  Wormian  bones,  and  where  are  they  found? 

Mention  the  several  names  given  to  non-articular  eminences. 

What  are  non-articular  depressions? 

THE   SPINAL  COLUMN. 

What  is  the  spine? 

How  many  bones  enter  into  its  formation? 
Into  how  many  regions  is  the  spine  divided? 
Give  the  number  in  each  region. 
What  is  a  vertebra? 
What  are  the  parts  of  a  vertebra? 
.What  do  the  several  parts  form? 
What  is  the  function  of  the  processes? 
What  does  the  arch  form? 

What  nerves  pass  through  between  the  vertebrae? 
What  does  the  atlas  support? 
With  what  bone  does  the  atlas  articulate? 
What  articulates  with  the  dorsal  vertebrae? 
With  what  does  the  sacrum  articulate? 
With  what  does  the  coccyx  articulate? 
What  is  the  average  length  of  the  spine? 
What  curves  does  it  present? 

Of  what  is  the  skull  considered  to  be  an  expansion? 
How  is  it  divided? 

How  many  bones  in  the  cranium?     The  face? 
What  does  the  occipital  bone  form? 
What  large  foramen  is  found  in  the  occipital  bone? 
What  do  the  parietal  bones  form? 
What  does  the  frontal  bone  form? 
What  is  found  in  the  infant  at  the  junction  of  the  frontal  and  parietal 

bones? 
What  important  relations  have  the  temporal  bones? 
Under  what  circumstances  may  this  bone  become  diseased? 
Where  are  the  sphenoid  and  ethmoid  bones  located? 
Where  are  the  superior  maxillary  bones  situated? 


OSTEOLOGY  49 

What  important  cavity  is  found  in  this  bone? 
How  many  cavities  does  this  bone  aid  in  forming? 
Give  the  location  of  the  malar  bones. 
What  bones  make  up  the  orbit? 
Where  are  the  palate  bones  situated? 
Where  are  the  turbinated  bones  found? 
What  is  the  vomer,  and  what  does  it  form? 
What  does  the  inferior  maxillary  bone  form? 
What  is  the  hyoid  bone?     Give  its  location. 

THORAX  AND  PELVIS. 

What  is  the  thorax? 
What  cavity  is  formed  by  the  thorax? 
What  bones  enter  into  its  formation? 
What  is  the  sternum,  and  how  is  it  divided? 
What  separates  the  thoracic  from  the  abdominal  cavity? 
How  many  ribs  go  to  make  up  the  thorax? 
How  are  the  ribs  divided? 
To  what  class  of  bones  do  the  ribs  belong? 
What  are  the  spaces  between  ribs  called? 
What  cavity  is  found  below  the  diaphragm? 
What  does  this  cavity  contain? 

What  do  you  understand  by  the  pelvis,  and  what  forms  the  same? 
How  is  the  pelvis  divided? 
What  is  contained  in  this  cavity? 
What  forms  the  outlet? 

What  is  the  average  transverse  diameter  of  the  pelvic  outlet? 
What  is  the  sacrum? 

How  many  bones  constitute  the  same,  and  at  what  age  do  they 
consolidate? 

What  is  the  coccyx,  and  to  what  is  it  predisposed? 

What  are  the  ossa  innominata,  and  what  do  they  form? 

Into  how  many  parts  are  they  divided?     Name  them. 

Give  the  locations  of  the  several  parts. 

What  passes  through  the  openings  in  this  bone? 

About  what  age  do  these  several  parts  become  consolidated? 

What  is  formed  by  the  union  of  the  ossa  innominata  anteriorly? 

BONES    OF   THE    UPPER   EXTREMITY. 

What  bones  form  the  shoulder-girdle? 
Describe  the  clavicle. 
4 


50        ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

With  what  bones  does  it  articulate? 

What  is  the  scapula? 

Where  is  it  located? 

What  important  processes  does  this  bone  present? 

What  cavity  is  formed  by  the  scapula? 

What  bone  articulates  in  this  cavity? 

To  what  class  of  bones  does  the  humerus  belong? 

With  what  bones  does  the  humerus  articulate? 

How  many  bones  form  the  upper  extremity? 

Which  bone  is  on  the  inner  side  of  the  forearm? 

With  what  does  the  ulna  articulate? 

Which  is  the  longest  bone  of  the  forearm? 

Does  the  ulna  enter  into  the  formation  of  the  wrist-joint? 

What  curved  process  is  presented  by  the  upper  end  of  the  ulna? 

What  cavity  is  formed  by  this  process? 

What  is  the  radius? 

With  what  does  it  articulate? 

What  is  the  fracture  called  which  occurs  at  its  lower  end? 

How  are  the  bones  of  the  hand  divided? 

How  many  bones  constitute  each  division? 

Name  the  bones  in  the  upper  row.     The  lower. 

What  part  of  the  hand  do  the  several  parts  form?   ^ 

LOAVER  EXTREMITY. 

What  is  the  femur,  and  with  what  does  it  articulate? 

To  \^at  class  of  bones  does  the  femur  belong? 

To  what  does  this  bone  give  attachment? 

What  bones  are  found  in  the  leg? 

Does  the  patella  enter  in  the  formation  of  the  knee-joint? 

What  is  the  tibia,  and  with  what  bones  does  it  articulate? 

What  is  formed  by  the  lower  extremity  of  the  bone? 

What  is  the  fibula? 

How  does  this  bone  articulate  with  the  tibia? 

What  is  formed  by  its  lower  extremity? 

What  is  the  patella? 

What  kind  of  a  bone  is  it? 

What  is  "house-maids  knee"? 

How  is  the  foot  divided? 

How  many  bones  are  in  each  division? 

What  is  the  uppermost  bone  of  the  tarsus? 

With  what  bone  does  it  articulate? 


OSTEOLOGY  5 1 

What  bone  forms  the  heel  proper? 

How  many  phalanges  are  there  in  the  foot? 

With  what  do  the  phalanges  articulate? 

ARTICULATIONS. 

What  are  articulations?     How  many  kinds  are  there? 

Where  do  we  find  sutural  ligaments? 

What  is  cartilage,  and  where  is  it  found? 

What  holds  the  joint  together? 

What  membrane  do  joints  contain? 

What  is  the  character  of  the  fluid  secreted  by  them? 

What  structures  enter  into  the  formation  of  joints? 

Why  is  the  term  synovia  used? 

How  are  joints  classified  according  to  their  range  of  motion? 

What  are  tendons? 

What  is  adipose  tissue?     State  its  functions. 

What  condition  is  caused  through  an  excess  of  adipose  tissue? 


I 


CHAPTER    II 
THE  MUSCULAR  SYSTEM 

The  muscles  constitute  the  fleshy  parts  of  the  body, 
and  are  the  main  organs  of  motion.  They  are  formed  of 
bundles  of  reddish  fibers,  endowed  with  the  property  of 
contractility.  These  bundles  of  fibers  are  enclosed  in  a 
delicate  web  called  the  perimysium,  in  contradistinction 
to  the  sheath  of  areolar  tissue  which  invests  the  en- 


^-fr 


Fig.  29. — Transverse  section  of  a  muscle,  magnified :  a,  Epimysium ;  b,  fas- 
ciculus ;  c,  perimysium  ;  d,  fiber. 

tire  muscle,  the  epimysium.  The  bundles  are  termed 
"fasciculi";  they  are  prismatic  in  shape  (see  Fig.  29),  of 
different  sizes  in  different  muscles,  and,  for  the  most  part, 
placed  parallel  to  one  another,  though  they  have  a  tend- 
ency to  converge  toward  their  tendinous  attachment. 
The  fasciculi,  or  bundles  of  fibers,  are  in  themselves 


THE   MUSCULAR   SYSTEM  53 

very  minute,  but  being  arranged  in  compound  bundles  of 
successively  larger  size,  we  have  ultimately  only  a  single 
bundle  in  a  muscle. 

The  essential  characteristic  of  a  muscle  is  its  contractil-  f, 
ity — it  contracts  in  length,  dilates  in  breadth,  its  body  i 
becoming  firm  and  rigid. 

Muscles  are  said  to  originate  at  the  point  where  they  \ 
have  the  most  fixed  attachment.     By  insertion  is  under-    1 
stood  the  opposite  end,  or  that  termination  or  attachment   / 
that  is  more  movable — that  is,  the  end  of  the  muscle  that 
most  moves  the  bone,  or  portions  to  which  it  is  attached. 
The  muscles  are  abundantly  supplied  with  blood-vessels 
and  nerves.     They  are  frequently  the  seat  of  rheumatic 
disorders,  as  well  as  of  inflammation. 

The  numbex_of_muscles  in  the  human  body  is  commonly 
estimated  at  405;  with  the  exception  of  9,  they  all  occur 
in  pairs. 

The  muscles  vary  widely  in  size  and  in  form.  In  the 
limbs  they  are  of  considerable  length;  this  is  true  es- 
pecially of  the  more  superficial  muscles,  the  deep  ones 
generally  being  broad.  They  surround  the  bones,  and 
form  an  important  protection  to  the  various  joints.  In 
the  trunk  the  muscles  are  broad,  flattened,  and  expanded, 
forming  the  parietes  of  the  cavities  which  they  enclose. 
For  purposes  of  description,  therefore,  muscles  are  termed 
long,  broad,  short,  etc. 

Each  muscle  is  invested  externally  by  a  thin  cellular 
layer,  forming  what  is  called  its  sheath :  this  not  only 
covers  its  outer  surface,  but  penetrates  its  interior,  in  the 
spaces  between  the  fasciculi,  surrounding  these,  and  serv- 
ing as  a  bond  of  connection  between  them. 

The  muscles  are  connected  with  the  bones,  cartilages, 
ligaments,  and  skin  either  directly  or  through  the  medium 
of  fibrous  structures  called  tendons  or  aponeuroses. 
(See  pages  46  and  47.) 


54 


ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 


The  muscles  are  capable  of  shortening  when  irritated 
mechanically  or  by  nerve-stimulus,  this  property  being 
called  "muscular  contractility  or  irritability." 

When  a  muscle  is  attached  to  bone  or  cartilage,  the 
fibers  terminate  in  broad,   blunt  extremities  upon  the 


Fig.  30. — Voluntary  muscle :  A,  Three  voluntary  fibers  in  long  sections : 
a,  Three  voluntary  muscle-fibers ;  b,  nuclei  of  same ;  c,  fibrous  tissue  be- 
tween the  fibers  (endomysium) ;  d,  fibers  separated  into  sarcostyles.  B, 
Fiber  (diagrammatic) :  a.  Dark  band ;  b,  light  band ;  c,  median  line  of 
Hensen ;  d,  membrane  of  Krause  ;  e,  sarcolemma ;  f,  nucleus.  C :  a,  Light 
band ;  b,  dark  band ;  c,  contracting  elements ;  d,  row  of  dots  composing  the 
membrane  of  Krause  ;  e,  slight  narrowing  of  contracting  element  aiding  in 
production  of  median  line  of  Hensen  (Leroy). 


periosteum  or  perichondrium,  and  do  not  come  into  direct 
relation  with  the  osseous  or  cartilaginous  tissue.  When 
muscles  are  connected  with  the  skin,  they  either  lie.  as  a 
flattened  layer  beneath  it,  or  are  connected  with  its  areo- 
lar tissue  by  larger  or  smaller  bundles  of  fibers,  as  in  the 
muscles  of  the  face. 


THE  MUSCULAR  SYSTEM  55 

The  muscles  of  the  body  are  of  two  kinds — the  Volun= 
tary  (striped  muscles),  which  are  capable  of  being  moved 
or  controlled  by  the  efforts  of  the  will,  and  the  involun= 
tary  (non-striped),  those  that  are  not  under  the  control 
of  the  will.  The  former  make  up  the  larger  bulk  of  the 
muscular  system ;  the  latter  are  found  in  the  blood-vessels 
and  in  the  walls  of  most  of  the  hollow  viscera. 

For  descriptive  purposes  the  muscles  of  the  body  are 
arranged  in  divisions  according  to  their  location:  as,  the 
head,  face,  and  neck  muscles ;  the  trunk  muscles ;  the  mus- 
cles of  the  upper  and  of  the  lower  extremities. 

As  has  been  previously  stated,  ia  this  connection  only 
the  most  important  points  that  a  nurse  should  know,  or 
become  familiar  with,  will  be  described;  as,  for  example, 
the  important  relation  each  organ  and  muscle  bears  to 
life,  its  action,  and,  in  the  case  of  the  muscles  of  the 
head  and  face,  the  role  they  play  in  lending  expression  to 
the  countenance. 

To  facilitate  description,  muscles  are  divided  into  groups 
that  take  their  names  from  the  regions  in  which  they  are 
located.  Thus  we  have,  in  the  head  and  face,  the  follow- 
ing regions:  the  epicranial,  auricular,  palpebral,  orbital, 
superior  maxillary,  inferior  maxillary,  temporomaxillary, 
pterygomaxillary,  etc. 

MUSCLES  OF  THE  HEAD  AND  FACE 
The  Occipital  Region. — ^The  first  muscle  to  be 
described  is  the  occipitofrontalis.  You  will  note  that 
the  prefix  occipito-  relates  to  the  occipital  bone,  and  the 
suffix  -frontalis,  to  the  frontal  bone,  showing  that  the  mus- 
cle extends  from  the  posterior  part  of  the  head  (occiput) 
to  the  eyebrows.  All  muscles  derive  their  names  in  this 
way,  and  if  students  will  study  these  names  carefully,  they 
will  become  fully  acquainted  with  the  origins  and  inser- 
tions of  the  muscles. 


56 


ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 


The  occipitofrontalis  is  a  broad,  musculofibrous  layer 
that  covers  the  vertex,  and  blends  in  front  with  the 
muscles  of  the  face  and  laterally  with  the  fascia  of  the 
temporal  muscles.  Action,  raises  the  eyebrows  and  the 
skin  of  the  nose  and  causes  the  transverse  wrinkles  of  the 
brow;  the  whole  scalp  may  be  moved  forward  and  back- 


FlG.  31. — Muscles  of  the  right  side  of  the  head  and  neck:  i,  Frontalis; 
2,  temporal;  3,  retrahens  aurem  ;  4,  orbicularis  palpebrarum;  5,  pyramid- 
alis  nasi;  6,  compressor  naris ;  7,  levator  labii  superioris  alseque  nasi;  8, 
levator  labii  superioris;  9,  zygomaticus  major;  10,  orbicularis  oris;  11,  de- 
pressor labii  inferioris ;  12,  depressor  anguli  oris ;  13,  anterior  belly  of 
digastric;  14,  mylohyoid;  15,  hyoglossus  ;  16,  stylohyoid;  17,  posterior  belly 
of  digastric;  18,  the  masseter ;  ig,  sternohyoid;  20,  anterior  belly  of  omo- 
hyoid; 21,  thyrohyoid;  22,  23,  lower  and  middle  constrictors  of  pharynx ; 
24,  sternomastoid ;  25,  26,  splenius  ;  27,  levator  scapulae;  28,  anterior  scale- 
nus; 29,  posterior  belly  of  omohyoid  ;  30,  middle  and  posterior  scalenus; 
31,  trapezius. 


ward  by  the  action  of  this  muscle.  It  is  involved  in  ex- 
pressing surprise  and  horror. 

Blood-supply,  from  the  occipital  and  posterior  auricular 
behind,  and  by  the  supra-orbital  and  anterior  temporal 
in  front. 

Nerve-supply,  posteriorly  by  the  posterior  auricular 
branch  of  the  facial,  and  exceptionally  from  the  occipital 


THE   MUSCULAR  SYSTEM  5/ 

minor  nerve.     Anteriorly,  by  the  temporal  branch  of  the 
temporofacial  division  of  the  facial. 

The   auricular  region   contains    the    three    **aurem 
muscles,"   which   are   placed   immediately   beneath   the 
skin  around  the  external  ear,  and  are  named  attoUens 
attrahens,  and  retrahens;  they  are  fan-shaped,  and  their 
fibers  converge  toward  the  pinna  or  auricle. 

These  muscles  possess  very  limited  movement:  the 
attoUens  slightly  raises  the  ear,  the  attrahens  draws  it 
forward  and  upward,  and  the  retrahens  draws  it  backward. 

The  palpebral  region  contains  four  muscles — the 
orbicularis  palpebrarum,  corrugator  supercilii,  levator 
palpebra,  and  tensor  tarsi. 

The   orbicularis   palpebrarum   is   a   sphincter   muscle  ^ 
and  surrounds  the  orbit  and  eyelids,  becoming  blended 
with  the  occipitofrontalis  and  the  corrugator  supercilii. 
ActioUy  closes  the  eyelids. 

The  corrugator  supercilii  is  a  small,  narrow,  pointed  ^ 
muscle,   situated   immediately   above   the   orbit,   at   the 
inner    extremity    of    the    eyebrow.     Action,    draws    the 
eyebrows  downward  and  inward. 

The  levator  palpebrae  will  be  considered  when  describ- 
ing the  muscles  of  the  orbital  region. 

The  tensor  tarsi  is  a  small,  thin  muscle.  Action,  draws 
the  eyelids  and  the  extremities  of  the  lacrimal  canal  in- 
ward and  compresses  them  against  the  globe  of  the  eye; 
in  this  position  they  receive  the  tears  that  are  secreted. 

Orbital  Region. — As  the  name  implies,  these  muscles  w 
are  connected  with  the  orbit;  there  are — i  levator  palpe- 
brae, 4  recti  (superior,  inferior,  internal,  and  external),  and  / 
2  oblique  (superior  and  inferior).  These  muscles  all  have 
their  special  attachments  to  the  several  parts  of  the  eye- 
ball, and  arise  from  the  bony  structure  that  encloses  it. 
Action,  to  control  the  movements  of  the  eye.  (Note  the 
arrangement  of  these  muscles  in  Fig.  32.) 


58        ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

Nasal  Region. — In  this  regicn  there  are  seven  pairs  of 
muscles,  which  control  the  lip  and  act  as  levers  to  lift  it; 
they  also  control  the  size  of  the  anterior  nares.  These 
are,  to  a  certain  degree,  muscles  of  expression;  each 
muscle  has  its  own  function  to  perform,  and  each  acts 
antagonistically  to  the  other — that  is,  some  dilate,  while 
others  constrict,  the  parts  concerned  in  their  movements. 


Fig.  32. — Muscles  of  the  orbit:  i,  Levator  palpebrae  superioris;  2,  ob- 
liquus  superior  ;  3,  pulley  of  obliquus  superior  ;  4,  rectus  superior;  5,  rectus 
inferior;  6,  rectus  externus  ;  7,  lower  head  of  rectus  externus;  8,  upper 
head  of  rectus  externus-;  10,  obliquus  inferior;  11,  optic  nerve  (Leidy). 


Superior  Maxillary  Region.— In  this  region  there 
are  four  muscles  on  each  side;  they  are  connected  to  the 
superior  maxillary  and  malar  bones,  and  arise  from  the 
lower  margin  of  the  orbit;  some  of  them  are  inserted  into 
the  muscular  substance  of  the  upper  lip.  They  are  named 
as  follows:  Levator  labii  superioris,  levator  anguli  oris, 
zygomaticus  major,  zygomaticus  minor.     (See  Fig.  31.) 

Action,  elevate  the  upper  lip;  draw  the  mouth  inward 
and  outward,  as  in  laughing  or  displaying  any  emotion, 


THE  MUSCULAR  SYSTEM  59 

as  they  are  able  to  alter  the  shape  of  the  mouth  so  that 
various  expressions  may  be  assumed. 

Inferior  Maxillary  Region. — Here  we  have  the 
levator  labii  inferioris,  depressor  labii  inferioris,  depressor 
anguli  oris.  Action  of  the  levator  labii  is  to  raise  the  lower 
lip;  it  also  protrudes  it,  and  at  the  same  time  wrinkles 
the  chin.  The  depressor  labii  inferioris  draws  the  lip 
downward  and  outward.  The  depressor  anguli  oris 
draws  the  angle  of  the  mouth  directly  backward.  These 
muscles  all  blend  with  other  muscles  of  the  face  (Fig.  31). 

Intermaxillary  Region.— Contains  the  orbicularis 
oris,  buccinator,  and  risorius.  The  orbicularis  oris  is  a 
sphincter  muscle,  elliptic  in  form,  and  surrounds  the  oral 
aperture  (mouth);  it  unites  with  the  buccinator  on  each 
side,  as  well  as  with  the  several  muscles  of  the  face. 
Action,  closes  the  lips. 

The  buccinator  is  a  broad,  thin  muscle.  Action ,  assists 
in  the  process  of  mastication;  compresses  the  cheeks,  so 
that  the  food  is  kept  in  immediate  contact  with  the 
teeth. 

The  risorius  has  its  insertion  in  the  angle  of  the  mouth. 
Action,  draws  out  the  angle  of  the  mouth  and  compresses 
the  cheek. 

Temporomaxillary  Region. — The  two  muscles  in 
this  region  are  of  great  importance;  they  are  named  the 
masse ter  and  the  temporal.  The  masseter  is  a  short, 
thick  muscle,  consisting  of  two  portions^superficial  and 
deep.  It  arises  from  the  malar  process  of  the  superior 
maxilla  and  zygomatic  arch,  and  is  inserted  into  the 
angle  of  the  lower  jaw.  Action,  a  muscle  of  masti- 
cation. 

The  temporal  is  a  broad  muscle,  situated  on  the  side  of 
the  head,  arising  from  temporal  fossa  and  fascia,  and  in- 
serted in  the  coronoid  process  of  the  inferior  maxillary 
bone.     Action,  assists  in  the  process  of  mastication. 


\ 


6o        ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

^  Pterygomaxillary  Region.— In  this  region  there  are 
two  muscles  on  each  side — the  internal  and  the  external. 
They  are  very  powerful  in  their  action. 

The  internal  pterygoid  is  a  thick,  quadrilateral  muscle, 
resembling  the  masseter  in  form  and  structure,  and  the 
fibers  run  in  about  the  same  direction. 

The  external  pterygoid  is  a  short,  thick  muscle,  broader 
at  its  base,  and  arises  by  two  heads — from  the  sphenoid 
bone  by  one  head,  and  from  the  pterygoid  plate  of  the 
ethmoid,  palate,  and  maxillary  bones  by  the  other. 
Insertion,  to  the  lower  jaw.  Action,  raises  the  lower  jaw 
with  great  force,  drawing  the  lower  jaw  forward  upon  the 
upper  jaw,  while  the  masseter  draws  it  backward,  assisted 
by  the  temporal ;  by  alternation  of  the  muscles  of  each  side 
the  food  is  comminuted  and  prepared  for  swallowing. 

MUSCLES   OF   THE   NECK 

The  muscles  of  the  neck  are :  Platysma  myoides,  sterno- 
cleidomastoid, sternohyoid,  sternothyroid,  thyrohyoid, 
omohyoid,  digastric,  stylohyoid,  geniohyoid,  geniohyoglos- 
sus,  hyoglossus,  styloglossus,  and  lingualis. 

Platysma  Myoides. — Arises  from  the  deep  fascia  over 
the  pectoral,  deltoid,  and  trapezius  muscles.  Insertion, 
in  the  lower  jaw  at  the  angle  of  the  mouth,  and  blends  with 
the  muscles  of  the  face.  Action,  depresses  the  jaw  and 
angle  of  the  mouth,  also  wrinkles  the  skin  of  the  neck; 
its  nerve-supply  is  obtained  from  the  facial  nerve,  through 
the  inframaxillary  branches. 
^  Sternocleidomastoid. — Arises  from  the  upper  part 
of  the  sternum  and  inner  border  of  the  clavicle.  Inserted 
in  the  mastoid  process  of  the  temporal  bone  and  two- 
thirds  of  curved  line  of  the  occipital  bone.  Action,  flexes 
the  head  on  the  neck  and  chest  and  rotates  the  chin  to 
the  opposite  side.  Nerve-supply,  from  the  spinal  acces- 
sory, second  and  third  cervical,  anterior  branches.     When 


THE   MUSCULAR  SYSTEM 


6i 


this  muscle  is  permanently  shortened  upon  one  side,  the 
resulting  condition  is  known  as  torticollis,  or  "wry-neck." 

Sternohyoid. — Arises  from  the  sternum  and  calvicle. 
Inserts  into  the  hyoid  bone.  Action,  depresses  the  hyoid 
bone. 

Sternothyroid. — Originates  in  the  posterior  part  of 
the  sternum  and  cartilage  of  the  first  rib.  Inserts  into 
the  thyroid  cartilage.     Action,  depresses  the  larynx. 


Fig.  33. — ^Muscles  of  the  neck  from  the  front :  On  the  left  side  the  pla- 
tysma  has  been  removed,  and  on  the  right  the  digastric,  the  stylohyoid, 
mylohyoid,  sternohyoid,  and  omohyoid  :  i.  Posterior,  and  i',  anterior  belly 
of  digastric  ;  2,  mylohyoid ;  3,  geniohyoid  ;  4,  hyoglossus  ;  5,  styloglossus  ;  6, 
stylohyoid;  7,  stylopharyngeus ;  8,  sternomastoid ;  9,  9',  omohyoid:  10, 
sternohyoid;  11,  12,  sternothyroid;  13,  levator  scapulae. 

Thyrohyoid. — Origin  from  the  thyroid  cartilage. 
Insertion  into  the  hyoid  bone.  Action,  elevates  the  larynx 
or  depresses  the  hyoid  bone. 

The  omohyoid  arises  from  the  scapula,  and  is  inserted 
into  the  hyoid  bone  and  cartilage  of  the  first  rib.  Action, 
depresses  the  hyoid  bone  and  larynx  and  draws  them 
backward  and  to  one  side. 

Digastric. — Arises  from  two  heads,  with  an  inter- 
mediate tendon;  is  attached  to  mastoid  process  of  the 
temporal  bone  and  lower  jaw.  Insertion,  into  the  hyoid 
bone.     Action,  raises  the  hyoid  bone  and  depresses  the 


62        ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

lower  jaw.  Nerve-supply  from  the  facial  and  inferior 
dental. 

Stylohyoid. — Arises  from  the  styloid  process  of  the 
temporal  bone.  Insertion,  into  the  body  of  the  hyoid  bone 
Action,  same  as  the  former. 

Geniohyoid. — Arises  from  the  inferior  tubercle  of  the 
lower  jaw  and  is  inserted  in  the  hyoid  bone.  Action,  same 
as  the  digastric. 

Qeniohyoglossus. — Originates  from  the  superior 
tubercle  of  the  lower  jaw.  Inserted  into  the  body  of  the 
hyoid  bone,  side  of  the  pharynx,  and  tongue  from  the  base 
to  the  tip.  Action,  protrudes  as  well  as  retracts  the  tongue ; 
it  also  produces  a  longitudinal  groove  in  this  organ,  as  in 
the  act  of  sucking.     Nerve-supply,  the  hypoglossal, 

Hyoglossus. — Arises  from  the  hyoid  bone;  inserted 
in  the  sides  of  the  tongue.  Action,  makes  this  organ  con- 
vex from  side  to  side.     Nerve-supply  from  the  hypoglossal. 

Styloglossus. — Arises  from  the  styloid  process  of 
the  temporal  bone.  Insertion,  into  the  side  of  the  tongue. 
Action,  draws  the  tongue  upward  and  backward.  Nerve, 
hypoglossal. 

Lingualis. — Forms  the  bulk  of  the  tongue,  and  is 
blended  with  the  other  muscles  which  are  attached  to  this 
organ.  Its  action  is  in  unison  with  that  of  the  other 
muscles. 

Palate  Region. — This  region  is  supplied  with  the 
following  muscles:  Levator  palati,  tensor  palati,  azygos 
uvulae,  palatoglossus,  palatopharyngeus.  They  arise 
from  adjacent  bony  structures  and  have  control  over  the 
soft  palate  and  uvula,  besides  assisting  in  the  acts  of 
speech,  deglutition,  and  mastication. 

Pharyngeal  Region. — The  muscles  found  in  the 
pharyngeal  region  are  the  following:  Three  constrictors — 
the  inferior,  the  superior,  and  the  medius;  the  stylopharyn- 
geus  and  the  palatopharyngeus. 


THE   MUSCULAR   SYSTEM  63 

The  inferior  constrictor  arises  from  the  cricoid  and  thy- 
roid cartilages,  and  is  inserted  into  its  fellow  of  the  opposite 
side.     Action,  constricts  the  pharynx  during  swallowing. 

The  middle  constrictor  has  its  origin  in  the  hyoid  bone 
and  stylohyoid  ligament.  Insertion,  into  its  fellow  of  the 
opposite  side.     Action,  same  as  inferior  constrictor. 

Ihe  superior  constrictor  arises  from  the  pterygoid  plate 
and  palate  bone,  as  well  as  from  the  hyoid.  Insertion, 
into  the  occipital  bone.  Action,  same  as  inferior  con- 
strictor. 

The  stylopharyngeus  arises  from  the  inner  side  of  the 
base  of  the  styloid  process  of  the  temporal  bone;  it  is 
inserted  into  the  thyroid  cartilage  and  blends  with  the 
constrictor  muscles.     Action,  elevates  the  pharynx. 

The  palatopharyngeus  has  its  origin  in  the  soft  palate. 
Insertion,  into  the  thyroid  cartilage  and  side  of  the 
pharynx.     Action,  closes  the  posterior  fauces. 

All  the  muscles  just  described,  except  the  palatopharyn- 
geus, are  controlled  by  the  spinal  accessory,  glossopharyn- 
geal, pharyngeal  plexus,  external  and  recurrent  laryngeal 
nerves;  the  palatopharyngeus  is  controlled  by  the  palato- 
glossus nerve. 

The  Pharynx. — The  pharynx  is  a  musculomembranous 
sac,  about  5  inches  long,  extending  from  under  the  base 
of  the  skull  to  a  point  corresponding  to  the  sixth  cervical 
vertebra.  It  is  widest  above  and  narrowest  below,  where 
it  terminates  in  the  esophagus.  It  is  attached  to  the 
styloid  processes  of  the  temporal  bone,  and  presents  seven 
openings:  the  two  posterior  nares,  two  Eustachian  tubes, 
the  mouth,  the  larynx,  and  the  esophagus.  For  purposes 
of  description  it  is  divided  into  three  parts — nasal,  oral, 
and  laryngeal.  It  is  attached  to  two  cartilages — the 
cricoid  and  the  thyroid — and  has  three  coats — an  internal 
mucous  membrane,  a  middle  fibrous  layer,  and  an  external 
muscular  coat. 


64        ^A^^  TOMY  AND  PHYSIOL  OG  Y  FOR  NURSES 

Anterior  Vertebral  Region. — This  region  con- 
tains four  muscles — the  rectus  capitis  anticus  major,  the 
rectus  capitis  anticus  minor,  the  rectus  lateralis,  the 
longus  colli.  The  lateral  vertebral  region  contains  three 
muscles — ^the  scalenus  anticus,  medius,  and  posticus. 
Action  of  the  several  muscles,  to  control  the  movements  of 
the  head  and  neck ;  by  means  of  their  several  attachments 
the  head  may  be  moved  in  any  direction. 

MUSCLES   OF   THE   TRUNK 

These  are  divided  into  groups,  according  to  the  region 
in  which  they  are  located :  thus  we  have  the  muscles  of  the 
back,  of  the  abdomen,  of  the  thorax,  and  of  the  perineum. 

The  muscles  of  the  back  are  divided  into  five  layers, 
of  which  the  more  superficial  layer  is  of  most  interest  to 
the  nurse.  (In  this  connection  the  illustrations  should 
be  carefully  studied,  in  order  that  an  accurate  knowledge 
of  the  construction  of  these  muscles  may  be  obtained.) 

The  first  of  these  to  be  described  is  the  large  muscle 
situated  at  the  upper  and  back  part  of  the  neck  and 
shoulders,  this  is  known  as  the  trapezius. 
•  Trapezius. — Origin,  from  the  occipital  bone  and  the 
processes  of  the  seventh  cervical  and  the  twelve  dorsal 
vertebrae,  as  well  as  from  the  ligamentum  nuchse.  In- 
sertion, into  the  clavicle  and  scapula.  Action,  draws  the 
shoulder  upward,  backward,  and  outward;  it  also  moves 
the  scapula  on  the  chest. 
/  Latissimus  Dorsi. — Origin,  from  the  six  lower  dorsal 
vertebrae  and  the  crest  of  the  ilium ;  being  a  broad  mus- 
cle, it  covers  the  lumbar  and  lower  half  of  the  sacral 
region,  and  is  one  of  the  most  important  muscles  of  the 
body.  Insertion,  into  the  humerus.  Action,  draws  the 
humerus  downward  and  backward  while  rotating  it  in- 
ward; it  raises  the  lower  ribs  in  forcible  inspiration;  it 


THE   MUSCULAR  SYSTEM 


65 


also  assists  the  other  muscles  of  the  chest,  as  in  climbing, 
pulling,  etc. 


Fig.  34. — Muscles  of  the  trunk  from  behind  (left  side,  superficial  ;  right 
side,  deep):  i,  Sternomastoid ;  2,  splenius ;  3,  trapezius;  4,  latissimus 
dorsi ;  5,  infraspinatus;  6,  teres  minor;  7,  teres  major;  8.  deltoid;  9,  ex- 
ternal oblique  of  abdomen;  10,  gluteus  medius ;  11,  gluteus  maximus  ;  12, 
levator  anguli  scapuloe  ;  13,  rhomboideus  minor;  14,  rhomboideus  major; 
15,  part  oif  longissimus  dorsi;  16,  tendons  of  insertion  of  iliocostalis ;  17, 
supraspinatus ;  18,  infraspinatus ;  19,  teres  minor;  20,  teres  major;  21,  ser- 
ratus  magnus  ;  22,  upper,  and  22',  lower  part  of  serratus  posticus  inferior; 
23,  internal  oblique  ;  24,  gluteus  medius ;  25,  pyriformis  and  superior  and 
inferior  gemelli ;  26,  26',  portions  of  obturator  internus  ;  27,  tendon  of  obtu- 
rator internus  ;  28,  quadratus  femoris. 


(The  student  should  refer  to  the  illustrations,  noting 
the  relation  that  the  several  muscles  bear  to  the  act  of 
respiration,  as  well  as  the  number  that  are  concerned  in  the 
act  of  moving  the  trunk  in  various  positions.) 
5 


66 


ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 


The  muscles  of  the  abdomen  are:  The  obhquus  ex- 
ternus;  obhquus  internus;  transversahs;  rectus;  pyramid- 
ahs,  and  quadratus  lumborum. 


Fig.  35. — Muscles  of  the  trunk  from  in  front  (left  side,  superficial ;  and 
right  side,  deep):  i,  Pectoralis  major;  2,  deltoid;  3,  portion  of  latissimus 
dorsi ;  4,  serratus  magnus ;  5,  subclavius ;  6,  the  pectoralis,  sternocostal 
portion;  7,  serratus  magnus;  12,  rectus  abdominis;  13,  internal  oblique; 
14,  external  oblique  ;  15,  abdominal  aponeurosis  and  tendinous  intersections 
of  rectus  abdominis;  16,  over  symphysis  pubis;  17,  linea  semilunaris;  18, 
gluteus  medius  ;  19,  tensor  vaginae  fern  oris ;  20,  rectus  femoris;  21,  sar- 
torius;  22,  femoral  part  of  iliopsoas;  23,  pectineus ;  24,  adductor  longus ; 
25,  gracilis. 

The  external  oblique  arises  from  the  eight  inferior  ribs ; 
it  is  inserted  into  the  anterior  half  of  the  iliac  crest,  and, 
mingling  with  its  fellow  of  the  opposite  side,  it  forms  the 
linea  alba.     It  is  connected  above  with  the  ensiform  carti- 


THE  MUSCULAR  SYSTEM  6^ 

lage,  and  below  with  the  pubis.  ^^That  portion  of  the 
aponeurosis  of  the  external  oblique  which  extends  from 
the  anterior  superior  spine  of  the  ilium  to  the  spine  of 
the  pubis  is  known  as  Poupart's  ligament.)  Gimbernat's 
ligament  is  an  extension  of  the  latter  to  the  iliopectineal 
line.  Action,  compresses  the  viscera,  flexes  the  thorax  on 
the  pelvis  or  the  pelvis  on  the  thorax,  according  to  which 
is  the  fixed  point,  and  also  assists  expiration.  Nerve- 
supply,  the  lower  intercostals. 

The  internal  oblique  arises  from  Poupart's  ligament, 
from  the  middle  lip  of  the  crest  of  the  ilium,  and  from  the 
lumbar  fascia.  Insertion,  crest  of  os  pubis  with  the  trans- 
versalis  muscle — forming  the  conjoined  tendon,  which 
strengthens  the  external  abdominal  ring;  it  also  blends 
with  the  external  oblique  to  form  the  linea  alba,  and  with 
the  transversalis  muscles.  Action,  same  as  that  of  the 
external  oblique.  Nerve-supply,  lower  intercostals,  ilio- 
hypogastric, and  ilio-inguinal. 

The  muscles  just  described  are  broad  and  cover  the 
greater  part  of  the  abdominal  wall;  they  are,  therefore, 
to  be  considered  in  operations  in  this  locality. 

The  muscles  of  the  abdomen  that  have  not  been  de- 
scribed may  be  studied  from  the  illustrations.  The 
student  should  observe  especially  the  linea  alba,  a  tendi'j 
nous  raphe  or  cord  seen  as  a  dark,  perpendicular  streak  inl 
the  middle  of  the  abdomen.  This  is  of  some  importance, 
and  is  of  interest  to  the  nurse,  especially  in  regard  to  the 
discoloration  that  takes  place  in  pregnant  women. 

Gray  says:  The  abdominal  muscles  have  a  threefold 
action:  They  compress  the  abdominal  wall  during  the 
process  of  defecation;  they  assist  in  the  act  of  respiration, 
and  they  help  in  the  expulsion  of  the  fetus;  the  urine  is 
expelled  through  the  agency  of  this  combination  of  mus- 
cular force,  and  by  it,  through  upward  pressure,  the  stom- 
ach is  relieved  of  its  contents.     From  this  it  will  be  seen 


68        ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

that  the  action  of  these  muscles  should  be  studied  closely, 
making  frequent  reference  to  the  illustrations. 

Muscles  of  the  Thorax. — The  muscles  of  the  thorax 
are  the  external  and  internal  intercostals,  the  infracos- 
tales,  the  triangularis  stemi,  and  the  levator  costarum; 
of  these,  the  most  important  are  the  intercostals.  They 
are  all  connected  with  the  bony  structure  of  the  thorax, 
and  are  all  concerned  in  respiration. 


Fig.  36. — The  diaphragm,  inferior  surface:  i,  2,  3,  Central  cordiform 
tendon ;  4,  5,  crura ;  6,  internal  arcuate  ligament ;  7,  external  arcuate  liga- 
ment ;  8,  aortic  opening;  9,  esophageal ;   10,  opening  for  vena  cava  (Leidy). 

*/  Diaphragmatic  Region. — The  diaphragm  is  a  thin, 
musculofibrous  septum,  separating  the  thorax  from  the 
abdominal  cavity.  It  is  divided  into  two  parts — a  greater 
and  a  lesser  portion.  It  is  convex  toward  the  chest;  its 
circumference  is  connected  with  the  ribs  and  the  vertebrae. 
It  contains  openings  for  the  transmission  of  the  aorta, 
esophagus,  vena  cava,  nerves,  arteries,  and  veins.  Action, 
a  muscle  of  respiration. 


THE  MUSCULAR  SYSTEM  69 


MUSCLES  OF   THE   UPPER   EXTREMITY 

MUSCLES  OF   THE    SHOULDER   AND   ARM 

Pectoralis  major.  Teres  major. 

Pectoralis  minor.  Teres  minor. 

Subclavius.  Coracobrachialis. 

Serratus  magnus.  Biceps  flexor  cubiti. 

Deltoid.  Brachialis  anticus. 

Subscapularis.  Triceps  extensor  cubiti. 

Supraspinatus.  Subanconeus. 


The  pectoralis  major  muscle  is  located  upon  the  chest. 
Origin,  from  the  clavicle,  sternum,  and  upper  six  costal 
cartilages.  Insertion,  into  the  humerus.  Action,  draws 
arm  downward  and  forward. 

Pectoralis  Minor. — Origin,  from  the  third,  fourth,  and 
fifth  ribs.  Insertion,  into  the  coracoid  process  of  the  scap- 
ula. Action,  depresses  the  shoulder  and  assists  in  the 
elevation  of  the  ribs  during  the  act  of  inspiration. 

The  subclavius  arises  from  the  first  costal  cartilage  and 
rib,  and  is  inserted  into  the  inner  surface  of  the  clavicle. 
Action,  draws  the  clavicle  downward. 

The  serratus  magnus  arises  by  nine  fleshy  digitations 
from  the  outer  surface  of  the  eight  upper  ribs ;  it  is  inserted 
into  the  posterior  border  of  the  scapula.  Action,  elevates 
ribs  in  inspiration;  fixes  scapula  in  act  of  pushing. 

The  deltoid  is  a  thick,  triangular  muscle  forming  the 
convexity  of  the  shoulder.  Origin,  from  the  upper  border 
of  the  clavicle,  outer  and  upper  surfaces  of  the  acromion 
process,  and  lower  border  of  the  scapula.  Insertion,  into 
the  outer  side  of  the  humerus.  Action,  raises  the  arm  to 
a  right  angle,  and  draws  it  forward  or  backward. 

The  subscapularis  arises  from  the  inner  two-thirds  of  the 
subscapular  fossa;  is  inserted  into  lesser  tuberosity  of  the 
humerus.  Action,  rotates  the  humerus  inward  as  well  as 
adducts  the  same.     Nerve,  subscapular. 


^ 


70        ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

The  supraspinatus  arises  from  the  supraspinous  fossa. 
Inserted  into  the  upper  facet  on  the  greater  tuberosity 
of  the  humerus.  Action,  assists  the  deltoid ;  fixes  the  head 
of  the  humerus  in  the  socket.     Nerve,  suprascapular. 


Fig.  38. 

Fig.  37. — Superficial  muscles  of  shoulder  and  arm  (from  in  front) :  i, 
Pectoralis  major;  2,  deltoid;  3,  biceps;  4,  brachialis  anticus;  5,  triceps;  6, 
pronator  radii  teres;  7,  flexor  carpi  radialis  ;  8,  palmaris  longus ;  9,  flexor 
carpi  ulnaris  10,  supinator  longus  ;  11,  extensor  ossis  metacarpi  pollicis  ;  12, 
extensor  brevis  pollicis;  13,  flexor  sublimis  digitorum  ;  14,  flexor  longus 
pollicis;  flexor  profundus  digitorum;  16,  palmaris  brevis;  17,  abductor 
pollicis. 

Fig.  38. — Superficial  muscles  of  shoulder  and  arm  (from  behind) :  i, 
Trapezius;  2,  deltoid;  3,  rhomboideus  major;  4,  infraspinatus;  5,  teres 
minor;  6,  teres  major;  7,  latissimus  dorsi ;  8,  triceps;  9,  anconeus;  10, 
brachialis  anticus  ;  11,  supinator  longus  ;  12,  extensor  carpi  radialis  longior  ; 
13,  extensor  carpi  radialis  brevior ;  14,  extensor  communis  digitorum  ;  15, 
extensor  carpi  ulnaris  ;  16,  flexor  carpi  ulnaris  ;  17,  extensor  ossis  metacarpi 
pollicis  ;  18,  extensor  brevis  pollicis  ;  19,  tendon  of  extensor  longus  pollicis. 


Infraspinatus. — Origin,  infraspinous  fossa.  Insertion, 
into  the  middle  facet  of  the  greater  tuberosity  of  the 
humerus.  Action,  rotates  the  humerus  outward.  Nerve, 
suprascapular. 


THE  MUSCULAR  SYSTEM  7 1 

Teres  Minor. — Origin,  upper  two-thirds  of  the  axillary 
border  of  the  scapula.  Insertion,  into  the  lower  facet  of 
the  greater  tuberosity  of  the  humerus.  Action ^  rotates 
the  humerus  outward.     Nerve,  circumflex. 

Teres  Major. — On'gm,  lower  border  of  infraspinous  fossa, 
and  is  inserted  into  the  bicipital  groove  of  the  humerus. 
Action,  draws  the  humerus  downward  and  backward,  when 
raised  also  rotates  it  inward.     Nerve,  lower  subscapular. 

Coracobrachialis. — Origin,  from  the  coracoid  process  of 
the  scapula.  Insertion,  middle  of  inner  side  of  the 
humerus.  Action,  draws  the  humerus  forward  and  in- 
ward, as  well  as  elevates  same.    Nerve,  musculocutaneous. 

Biceps  Flexor  Cubiti. — Origin,  by  two  heads:  Short 
head,  from  the  coracoid  process  of  the  scapula;  long  head, 
from  upper  margin  of  the  glenoid  cavity  by  a  round  tendon 
continuous  with  the  glenoid  ligament.  Insertion,  by  a 
tendon  into  the  back  part  of  the  tuberosity  of  the  radius 
and  by  an  aponeurosis  into  the  fascia  of  the  forearm,  which 
renders  this  fascia  tense.     Nerve,  musculocutaneous. 

Brachialis  Anticus. — Origin,  anterior  surface  of  the 
humerus,  embracing  the  insertion  of  the  deltoid.  In- 
sertion, into  the  inferior  surface  of  the  coronoid  process  of 
the  ulna.  Action,  flexes  the  forearm.  Nerve,  musculo- 
cutaneous and  musculospiral. 

Triceps  Extensor  Cubiti. — Origin,  arises  by  three  heads, 
the  long,  external,  and  internal;  long  head,  from  the 
glenoid  fossa,  the  external,  from  the  posterior  surface  of 
the  shaft  of  the  humerus  between  the  upper  part  of  the 
musculospiral  groove  and  the  insertion  of  the  teres  minor ; 
internal,  from  the  posterior  surface  below  the  musculo- 
spiral groove.  Insertion,  into  the  olecranon  process 
of  the  ulna.  Action,  extends  the  forearm.  Nerve,  mus- 
culospiral. 

Subanconeus. — Origin,  above  the  olecranon  fossa  of  the 
humerus.     Insertion,  into  the  posterior  ligament  of  the 


72 


ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 


elbow.     Action,  prevents  the  capsule  from  injury  during 
extension  of  the  arm.     Nerve,  musculospiral. 

MUSCLES  OF  THE  FOREARM 

f  Pronator  teres. 
Flexor  carpi  radialis. 
Superficial  layer :  -    Palmaris  longus. 

Flexor  carpi  ulnaris. 
^  Flexor  sublimis  digitorum. 


{Flexor  profundus  digitorum. 
Flexor  longus  pollicis. 
Pronator  quadratus. 

r  Supinator  longus. 
-j   Extensor  carpi  radialis  longior. 
[  Extensor  carpi  radialis  brevior. 

C  Extensor  communis  digitorum. 
Posterior  radio-ulnar  region  J   Extensor  minimi  digiti. 
{juper/icial  layer)  :  <  Extensor  carpi  ulnaris. 

[^  Anconeus. 


Deep  layer  : 


Radial  region 


Deep  layer  : 


Supinator  brevis. 
Extensor  ossis  metacarpi  pollicis. 
Extensor  brevis  pollicis. 
Extensor  longus  pollicis. 
Extensor  indicis. 


The  pronator  teres  arises  from  the  internal  condyle  of 
the  humerus  and  from  the  coronoid  process  of  the  ulna. 
Inserted,  outer  side  of  shaft  of  radius.  Action,  pronates 
forearm.     Nerve,  median. 

Flexor  Carpi  Radialis. — Origin,  internal  condyle  of 
humerus.  Insertion,  metacarpal  bone  of  index-finger. 
Action,  flexes  wrist.     Nerve,  median. 

Palmaris  Longus. — Origin,  from  internal  condyle. 
Insertion,  in  the  annular  ligament  and  palmar  fascia. 
Action,  makes  the  palmar  fascia  tense.     Nerve,  median. 

The  flexor  carpi  ulnaris  arises  by  two  heads:  First, 
from  the  internal  condyle;  second,  from  the  olecranon 


THE   MUSCULAR   SYSTEM  73 

process  of  the  ulna.  Insertion,  fifth  metacarpal  bone, 
annular  ligament,  and  pisiform  bone.  Action,  flexes  the 
wrist.     Nerve,  ulnar.     (See  Figs.  37  and  38.) 

Flexor  Sublimis  Digitorum. — Origin,  by  three  heads: 
First,  from  the  inner  condyle;  second,  coronoid  process  of 
ulna;  third,  oblique  line  of  radius.  Insertion,  into  the 
second  phalanges  by  four  tendons.  Action,  flexes  second 
phalanges.     Nerve,  median. 

The  flexor  profundus  digitorum  arises  from  shaft  of 
ulna.  Insertion,  into  last  phalanges  by  four  tendons. 
Action,  flexes  the  phalanges.     Nerve,  median. 

Flexor  Longus  PoUicis. — Origin,  shaft  of  radius  and 
coronoid  process  of  ulna.  Insertion,  last  phalanx  of 
thumb.  Action,  flexes  the  phalanx.  Nerve,  anterior 
interosseous. 

Pronator  Quadratus. — Origin,  from  lower  fourth  of 
ulna.  Inserted,  in  lower  one-fourth  of  radius.  Action, 
pronates  the  hand.     Nerve,  anterior  interosseous. 

Supinator  Longus. — Origin,  upper  two-thirds  of  external 
condyloid  ridge  of  humerus.  Insertion,  styloid  process  of 
radius.     Action,  flexes  forearm.     Nerve,  musculospiral. 

Extensor  Carpi  Radialis  Longior. — Origin,  lower  one- 
third  of  external  condyloid  ridge  of  humerus.  Insertion, 
base  of  second  metacarpal  bone.  Nerve,  musculospiral. 
Action,  extends  wrist. 

Extensor  Carpi  Radialis  Brevior. — Origin,  external  con- 
dyle of  humerus.  Insertion,  base  of  second  and  third 
metacarpal  bones.  Action,  extends  wrist.  Nerve,  pos- 
terior interosseous. 

Extensor  Communis  Digitorum. — Origin,  external  con- 
dyle of  humerus.  Insertion,  the  second  and  third  pha- 
langes. Action,  extends  the  fingers.  Nerve,  posterior 
interosseous. 

Extensor  Minimi  Digiti. — Origin,  external  condyle  of 
humerus.     Insertion,  in  the  second  and  third  phalanges  of 


74        ANATOMY  AND  PHYSIOLOGY  FOR   NURSES 

little  finger.  Action,  extensor  of  little  finger.  Nerve, 
posterior  interosseous. 

Extensor  Carpi  Ulnaris. — Origin,  by  two  heads:  First 
head,  external  condyle  of  humerus ;  second  head,  posterior 
border  of  ulna.  Insertion,  base  of  fifth  metacarpal  bone. 
Action,  extends  wrist.     Nerve,  posterior  interosseous. 

Anconeus. — Origin,  back  and  external  condyle  of  hu- 
merus. Insertion,  olecranon  process  and  shaft  of  ulna. 
Action,  extends  forearm.     Nerve,  musculospiral 

Supinator  Brevis. — Origin,  external  condyle  o  Tierus 
and  oblique  line  of  ulna.  Insertion,  neck  of  rad  ^nd  its 
bicipital  tuberosity.  Action,  supinates  the  forearm. 
Nerve,  posterior  interosseous. 

Extensor  Ossis  Metacarpi  PoUicis. — Origin,  back  of 
radius  and  ulna  and  interosseous  membrane.  Insertion, 
base  of  metacarpal  bone  of  thumb  and  fascia.  Action, 
extends  the  thumb.     Nerve,  posterior  interosseous. 

Extensor  Brevis  Pollicis. — Origin,  back  of  radius. 
Insertion,  inner  part  of  the  base  of  first  phalanx  of 
thumb.  Action,  extends  the  first  phalanx  of  thumb  and 
abducts  the  wrist.     Nerve,  posterior  interosseous. 

Extensor  Longus  Pollicis. — Origin,  posterior  part  of  the 
ulna  and  interosseous  membrane.  Action,  extends  second 
phalanx  of  the  thumb  and  abducts  the  wrist.  Nerve, 
posterior  interosseous. 

Extensor  Indicis. — Origin,  posterior  part  of  ulna.  Inser- 
tion, second  and  third  phalanges  of  index-finger.  Action, 
extends  the  index-finger.     Nerve,  posterior  interosseous. 

MUSCLES  OF  THE  HAND 

Abductor  pollicis.  Abductor  minimi  digiti. 

Opponens  pollicis.  Flexor  brevis  minimi  digiti. 

Flexor  brevis  pollicis.  Opponens  minimi  digiti. 

Abductor  obliquus  pollicis.  Lumbricales. 

Adductor  transversus  pollicis.  Dorsal  interossei  (4). 

Palmaris  brevis.  Palmar  interossei  (3). 


THE  MUSCULAR  SYSTEM  75 

Abductor  Pollicis. — Origin,  from  trapezium,  scaphoid, 
annular  ligament,  and  palmar  fascia.  Insertion,  first 
phalanx  of  thumb.  Action,  abducts  and  flexes  first  pha- 
lanx of  thumb.     Nerve,  median. 

Opponens  Pollicis. — Origin,  trapezium  and  anterior 
ligament.  Insertion,  metacarpal  bone  of  thumb.  Action, 
flexes  and  opposes  thumb.  Nerve,  median,  palmar  divis- 
ion. 

Flexor  Brevis  Pollicis. — Origin,  by  two  heads:  Outer, 
lower  border  of  superior  annular  ligament  and  ridge  of 
trapezium;  inner,  os  magnum,  and  base  of  first,  second, 
and  third  metacarpal  bones.  Insertion,  base  of  first 
phalanx  of  thumb.  Action,  flexes  the  thumb  at  meta- 
carpal articulation.  Nerve,  outer  head,  median;  inner 
head,  deep  ulnar. 

Adductor  Obliquus  Pollicis. — Origin,  from  os  magnum, 
second  and  third  metacarpal  bones.  Insertion,  base  of 
first  phalanx  of  thumb.  Action,  draws  the  thumb  inward 
toward  the  middle  line.     Nerve,  ulnar. 

Adductor  Transversus  Pollicis. — Origin,  third  metacar- 
pal bone.  Insertion,  base  first  phalanx  of  thumb.  Ac- 
tion, flexes  the  phalanx,  adducts  the  thumb.  Nerve, 
ulnar. 

Palmaris  Brevis. — Origin,  from  the  annular  ligament 
and  palmar  fascia.  Insertion,  skin  on  inner  border  of 
palm.  Action,  wrinkles  the  skin  on  the  palmar  side. 
Nerve,  ulnar. 

Abductor  Minimi  Digiti. — Origin,  pisiform  bone.  In- 
sertion, base  of  first  phalanx  of  little  finger.  Action,  draws 
the  little  finger  from  the  middle  line  and  flexes  the  meta- 
carpophalangeal joint.     Nerve,  ulnar. 

Flexor  Brevis  Minimi  Digiti. — Origin,  from  the  unciform 
bone  and  annular  ligament.  Insertion,  first  phalanx  of 
little  finger.  Action,  flexes  the  first  phalanx.  Nerve, 
ulnar. 


76        ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

Opponens  Minimi  Digiti. — Origin,  from  the  unciform 
bone.  Insertion,  whole  length  of  the  fifth  metacarpal 
bone.  Action,  flexes  the  fifth  metacarpal,  draws  it  forward, 
and  makes  the  hollow  of  the  palm  of  hand.    Nerve,  ulnar. 

Lumbricales. — Origin,  tendon  of  the  deep  flexors. 
Insertion,  in  the  dorsum  of  each  finger.  Action,  flex  the 
first  and  extend  the  last  two  phalanges.  Nerve,  two  outer 
by  the  median,  two  inner  by  the  ulnar. 

Dorsal  Interossei. — Origin,  four  in  number  by  two 
heads,  from  the  sides  of  the  metacarpal  bones.  Insertion, 
into  base  of  first  phalanges  of  fingers.  Action,  flex  the 
first  and  extend  the  last  two  phalanges,  abduct  the 
fingers.     Nerve,  ulnar. 

Palmar  Interossei  (three  in  number) . — Origin,  by  single 
heads,  from  the  palmar  side  of  the  second,  fourth,  and 
fifth  metacarpals.  Insertion,  into  the  second,  fourth,  and 
fifth  phalanges.  Action,  flex  the  first,  extend  the  last  two 
phalanges,  adduct  the  fingers  toward  the  middle  line. 
Nerve,  ulnar. 

MUSCLES    OF   THE   LOWER    EXTREMITY 

For  convenience  in  description  the  muscles  of  the  leg 
will  be  divided  into  groups  according  to  their  various  loca- 
tions, only  the  most  important  ones  with  which  the  nurse 
should  become  acquainted  being  described. 
The  muscles  of  the  iliac  or  inguinal  region  are: 
Psoas  magnus. 
Psoas  parvus. 
Iliacus. 
^      The  psoas  magnus  is  a  long,  fusiform  muscle,  situated 
on  the  side  of  the  lumbar  region  of  the  spine  and  margin  of 
the  pelvis.     Origin,  from  the  transverse  processes  of  the 
last  thoracic  and  of  all  the  lumbar  vertebrae.     Insertion, 
into  the  lesser  trochanter  of  the  femur.     Action,  flexes 
the  thigh  on  the  pelvis,  or  vice  versa;  also  rotates  the  femur 


THE   MUSCULAR   SYSTEM 


77 


outward.     Nerve-supply,  anterior  branches  of  the  second 
and  third  lumbar. 

The  psoas  parvus  is  a  long,  slender  muscle,  situated  in 
front  of  the  psoas  magnus.  It  arises  from  the  last  thoracic 
and  the  first  lumbar  vertebrae.  In- 
sertion,  iliac  fascia  and  iliopectineal 
eminence.  Action,  makes  the  iliac 
fascia  tense.  Nerve,  anterior  branch 
of  first  lumbar. 

><  The  iliacus  is  a  flat,  radiated 
muscle  that  fills  up  the  whole  of 
the  iliac  fossa  (internal),  from 
which  point,  as  well  as  from  the 
inner  margin  of  the  iliac  crest  and 
sacrum,  it  originates.  Inserted, 
with  the  tendon  of  the  psoas  mag- 
nus, into  the  lesser  trochanter  of 
the  femur.  Action,  same  as  the 
psoas  magnus.  Nerve,  anterior 
crural. 

The   muscles    of   the    anterior 
femoral  region  are: 


Fig.  39. — Superficial 
muscles  ot  hip  and  thigh 
(from behind) :  i, Gluteus 
medius  ;  2,  gluteus  maxi- 
mus  ;  3.  vastus  externus ; 
4,  biceps  flexor  cruris ;  5, 
semitendinosus ;  6,  semi- 
membranosus ;  7,  gra- 
cilis ;  8,  sartorius  ;  9,  ad- 
ductor magnus ;  10,  11, 
gastrocnemius;  12,  origin 
of  plantaris. 


Tensor  vaginae  femoris. 

Sartorius. 

Rectus  femoris. 

Vastus  externus. 

Vastus  intemus. 

Crureus. 

Subcrureus. 

The  tensor  vaginae  fiemoris  is  a  short,  flat  muscle,  situ- 
ated at  the  upper  and  outer  side  of  the  thigh.  Origin, 
outer  part  of  the  crest  of  the  ilium  and  anterior  superior 
spinous  process.  Inserted  in  the  fascia  lata  at  the  outer 
side  of  the  thigh.  Action,  internal  rotator  of  the  thigh. 
Nerve,  superior  gluteal. 


78 


ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 


X  The  sartorius,  the  longest  muscle  in  the  body,  is  a  flat, 
narrow,  ribbon-like  muscle  that  arises  from  the  anterior 
superior  spinous  process  of  the  ilium,  passing  down  the 


Fig.  40.  Fig.  41.  Fig.  42. 

Fig.  40. — Muscles  of  the  inner  side  of  thigh  and  interior  of  pelvis:  i, 
Iliacus;  2,  psoas  magnus ;  3,  obturator  internus;  4,  pyriformis;  5,  erector 
spinae;  6,  gluteus  maximus;  7,  sartorius;  8,  adductor  longus;  9,  gracilis; 
10,  adductor  magnus ;  11,  semimembranosus ;  12,  semitendinosus ;  13,  rectus 
femoris  ;  14,  vastus  internus. 

Fig.  41. — Superficial  muscles  of  the  leg  from  inner  side:  1,  Vastus  in- 
ternus; 2,  sartorius;  3,  gracilis;  4,  semitendinosus;  5,  semimembranosus; 

6,  inner  head  of  gastrocnemius;  7,  soleus;  8,  tendonof  plantaris  ;  g,  tendon 
of  tibialis  posticus ;  10,  flexor  longus  digitorum  ;  11,  flexor  longus  hallucis ; 
12,  tibialis  anticus  ;  13,  abductor  hallucis. 

Fig.  42. — Superficial  muscles  of  front  of  thigh:  1,  Insertion  of  external 
oblique  into  iliac  crest;  2,  aponeurosis  of  external  oblique  ;  3,  external  ab- 
dominal ring;  4,  gluteus  medius;   5,  tensor  vaginae  femoris;    6,  sartorius; 

7,  iliopsoas;  8,  pectineus ;  9,  adductor  longus;  10,  gracilis;  11,  adductor 
magnus;  12,  vastus  externus ;  13,  rectus  femoris;  14,  vastus  internus;  15, 
biceps  flexor  cruris. 


inner  side  of  the  thigh  vertically  to  the  inner  side  of  the 
knee.  Insertion,  into  the  inner  surface  of  the  shaft  of  the 
tibia.     Action,  flexes  the  leg  upon  the  thigh,  as  well  as 


THE  MUSCULAR  SYSTEM 


79 


the  thigh  upon  the  pelvis.  Also  called  the  tailors'  muscle. 
Nerve,  anterior  crural. 

<  The  rectus  f emoris  arises  from  the  anterior  inferior  iliac 
spine.  Insertion^  in  the  patella.  Action,  flexes  the  hip- 
joint.     Nerve,  anterior  crural. 


Fig.  43.  Fig.  44. 

Fig.  43.— Muscles  of  leg  and  foot  (from  before):  i,  Tendon  of  rectus 
femoris;  2,  vastus  internus  ;  3,  vastus  extern  us  ;  4,  sartorius  ;  5,  iliotibial  band; 
6,  inner  head  of  gastrocnemius;  7,  inner  part  of  soleus;  8,  tibialis  anticus; 
9,  extensor  propnus  hallucis ;  10,  ext^sor  longus  digitorum  ;  11,  peroneus 
longus;  12,  peroneus  brevis;  13,  peroneus  tertius;  14,  origin  of  extensor 
brevis  digitorum. 

Fig.  44-— Superficial  muscles  of  leg  (from  behind)  :  i,  Vastus  externus; 
2,  biceps  flexor  cruris  ;  3,  semitendinosus  ;  4,  semimembranosus ;  5,  gracilis; 
6  sartorius;  7,  outer,  and  8,  inner,  head  of  gastrocnemius  ;  9,  plantaris;  10, 
soleus;  11,  peroneus  longus;  12,  peroneus  brevis;  13,  flexor  longus  digi- 
torum;  14,  tibialis  posticus;  15,  lower  fibers  of  flexor  longus  hallucis. 


Vastus  Externus.— On^m,  tubercle  of  the  femur  and 
the  great  trochanter.  Inserted  into  the  outer  side  of  the 
patella.     Action,  extends  the  leg.     Nerve,  anterior  crural. 


So        ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

Vastus  Intemus  and  Crureus. — Origin,  from  the  inner 
side  of  the  femur.  Insertion,  into  the  patella.  Action, 
extends  the  leg.     Nerve,  anterior  crural. 

Subcrureus. — Arises  by  two  heads  from  the  femur. 
Inserted  in  the  upper  portion  of  the  synovial  pouch  of  the 
knee-joint.     Action,    draws    the    synovial    sac    upward. 
Nerve,  anterior  crural. 
The  muscles  of  the  internal  femoral  region  are: 
Gracilis.  Adductor  longus. 

Pectineus.  Adductor  magnus. 

Adductor  brevis. 
Gracilis. — Origin,   ramus    of   the  os  pubis.      Inserted 
into  the  inner  side  of  the  tibia.     Action,  flexes  the  leg, 
rotates  it  inward,   and  adducts  the  thigh.     Nerve,  the 
obturator. 

Pectineus. — Origin,  from  the  iliopectineal  line.  In- 
serted into  the  lesser  trochanter.  Action,  flexes  and  ad- 
ducts the  thigh.  Nerves,  anterior  crural  and  obturator. 
The  adductor  longus  magnus  and  brevis  arise  from  the 
OS  pubis,  and  are  inserted  into  the  inner  side  of  the  femur. 
Action,  adduct,  rotate,  and  flex  the  thigh.  Nerve,  obtu- 
rator and  sciatic. 

The  gluteal  region  contains  the  largest  muscles  of 
the  body;  these  are  as  follows: 

Gluteus  maximus.  Obturator  internus. 

Gluteus  medius.  Gemellus  superior. 

Gluteus  minimus.  Gemellus  inferior. 

Pyriformis.  Obturator  externus. 

Quadratus  femoris. 
-^  The  gluteus  maximus  is  the  most  superficial  muscle  in 
this  region.  It  is  a  broad,  thick,  fleshy  muscle,  quadri- 
lateral in  shape,  and  forms  the  nates;  it  is  the  most  im- 
portant muscle  in  maintaining  the  body  in  an  erect  pos- 
ture. It  arises  from  the  ilium,  sacrum,  and  coccyx,  and  is 
inserted  into   the   great  trochanter.     Action,   holds   the 


THE  MUSCULAR  SYSTEM  Si 

trunk  erect,  extends,  abducts,  and  rotates  the  thigh 
outward.      Nerve,  inferior  gluteal. 

Gluteus  Medius. — Arises  from  the  outer  surface  of  the 
ilium.  It  is  inserted  into  the  great  trochanter.  Action, 
supports  the  trunk,  flexes  and  abducts  the  thigh,  and  ro- 
tates it  inward.     Nerve,  superior  gluteal. 

Gluteus  Minimus. — Arises  from  the  outer  side  of  the 
ilium,  and  is  inserted  in  the  great  trochanter.  Action, 
flexes,  abducts,  and  rotates  the  thigh  inward;  it  also  assists 
in  holding  the  trunk  erect.     Nerve,  superior  gluteal. 

The  pyriformis  is  a  flat  muscle,  arising  by  three  digita- 
tions  from  the  sacrum  and  ilium.  It  is  inserted  into  the 
great  trochanter.  Action,  rotates  thigh  outward,  abducts 
it  as  well,  and  draws  the  pelvis  forward.  Nerves,  branches 
of  sacral  plexus. 

The  obturator  intemus  is  situated  partly  in  the  pelvis, 
and  arises  from  the  margin  of  the  obturator  foramen. 
It  is  inserted  into  the  inner  part  of  the  great  trochanter. 
Action,  draws  the  pelvis  forward  and  assists  in  external 
rotation  and  abduction  of  the  thigh.  Nerve,  branch  of  the 
sacral  plexus. 

Gemellus  Superior. — Arises  from  the  ischium,  and  is 
inserted  into  the  inner  part  of  the  great  trochanter. 
Action,  rotates  the  thigh  outward.  Nerve,  branch  of 
sacral  plexus. 

Gemellus  Inferior. — Arises  from  the  ischium,  and  is 
inserted  into  the  great  trochanter  of  the  femur.  Action, 
external  rotator  of  thigh.     Nerve,  branch  of  sacral  plexus. 

The  obturator  extemus  is  a  flat,  triangular  muscle, 
situated  on  the  outside  of  the  pelvis.  Arises  from  the 
margin  of  obturator  foramen,  and  is  inserted  into  the 
femur.  Action,  rotates  thigh  outward.  Nerve-supply, 
from  branch  of  obturator. 

The  quadratus  femoris  is  a  short,  flat  muscle,  quadri- 
lateral in  shape.  Origin,  from  the  tuberosity  of  the 
6 


82        ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

ischium.  Insertion,  into  the  posterior  intertrochanteric 
Hne.  Action,  abducts  the  thigh  and  rotates  it  outward. 
Nerve,  branch  of  the  sacral  plexus. 

The  muscles  of  the  posterior  femoral  region  are 
the  biceps,  the  semitendinosus,  and  the  semimembrano- 
sus. 

The  biceps  is  a  large  muscle  situated  on  the  outer  part 
of  the  thigh.  It  arises  by  two  heads,  the  long  from  the 
tuberosity  of  the  ischium  and  the  short  from  the  linea 
aspera.  Insertion,  head  of  the  fibula,  the  tendon  thereof 
splitting,  one  band  embracing  the  lateral  ligament  and  the 
other  extending  to  the  outer  tuberosity  of  the  tibia;  this 
muscle  is  called  the  outer  hamstring.  Action,  extends  the 
hip,  flexes  the  leg,  after  which  it  rotates  it  outward. 
Nerve,  great  sciatic. 

The  semitendinosus  is  situated  on  the  inner  side  of  the 
thigh ;  this  is  a  remarkable  muscle,  as  it  is  provided  with 
a  very  extensive  tendon.  It  arises  from  the  tuberosity 
of  the  ischium  and  is  associated  with  the  biceps;  it  con- 
tinues downward,  the  muscular  belly  becoming  ten- 
dinous a  little  below  the  middle  of  the  thigh.  It 
is  inserted  into  the  upper  and  inner  part  of  the  tibia. 
Action,  extends  the  hip,  flexes  the  leg  on  the  thigh,  and 
rotates  it  inward.     Nerve,  great  sciatic. 

The  semimembranosus  arises  from  the  tuberosity  of  the 
ischium.  It  is  inserted  into  the  inner  and  back  part  of  the 
tuberosity  of  the  tibia.  Action,  flexes  the  leg  on  the  thigh 
and  rotates  it  inward.      Nerve,  great  sciatic. 

Muscles  of  the  Leg. — Having  studied  the  muscles  of 
the  thigh  and  hip,  those  of  the  leg  and  foot  will  now  be 
considered.  Of  these,  only  the  most  important,  and  es- 
pecially the  most  superficial,  will  be  described. 

There  are  thirteen  muscles  in  the  \^g\  these  are  as 
follows : 

The  tibialis  anticus,  extensor    longus    digitorum,  ex- 


THE   MUSCULAR   SYSTEM  83 

tensor  longus,  hallucis,  peroneus  tertius,  gastrocnemius, 
plantaris,  popliteus,  flexor  longus  hallucis,  flexor  longus 
digitorum,  tibialis  posticus,  peroneus  longus,  peroneus 
brevis. 

The  deep  fascia  forms  a  complete  investment  of  the 
entire  region  of  the  leg,  and  is  attached  to  the  inner  side 
of  the  tibia. 

The  tibialis  anticus  is  a  thick,  fleshy  muscle,  situated  on  ^ 
the  outer  side  of  the  tibia.  It  arises  from  the  tuberosity 
and  shaft  of  the  tibia,  the  fibers  thereof  terminating  in  a 
tendon  that  passes  under  the  annular  ligament  and  is 
inserted  into  the  internal  cuneiform  bone  and  base  of  the 
first  metatarsal.  Action,  flexes  the  ankle-joint  and  raises 
the  inner  border  of  the  foot.     Nerve,  anterior  tibial. 

The  extensor  longus  hallucis  is  a  thin,  elongated,  and 
flattened  muscle.  It  arises  from  the  anterior  surface  of  the 
fibula  and  from  the  interosseous  membrane ;  the  fibers  pass 
downward  and  terminate  in  a  tendon  that  passes  under  the 
annular  ligament,  and  is  inserted  in  the  last  phalanx  of 
the  great  toe.  Action,  same  as  the  tibialis  anticus.  Nerve, 
anterior  tibial. 

The  extensor  longus  digitorum  is  an  elongated,  flattened 
muscle,  situated  most  externally  of  all  the  muscles  in  front 
of  the  leg.  It  arises  from  the  tuberosity  of  the  tibia 
and  shaft  of  the  fibula,  extends  downward,  and  divides 
into  four  tendons,  which  are  inserted  in  second  and  third 
phalanges  of  the  four  lesser  toes.  Action,  extends  the  toes, 
flexes  the  ankle,  and  everts  the  foot.  Nerve,  anterior 
tibial. 

The  gastrocnemius,  the  most  important  muscle  of  the  ><s 
posterior  part  of  the  leg,  is  an  elongated,  flattened  muscle. 
It  forms  the  calf  proper.  It  arises  from  the  condyles  of 
the  femur  by  two  heads.  Insertion,  with  the  tendons  of 
the  soleus  and  plantaris  to  form  the  tendo  Achillis,  which 
is  finally  inserted  into  the  tuberosity  of  the  os  calcis. 


84        ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

Action,  extends  the  foot  and  rotates  it  slightly  inward. 
Nerve,  internal  popliteal. 

The  nurse  should  ascertain,  from  the  illustrations,  the 
location  of  the  other  muscles  of  the  leg,  particularly  of  the 
flexors,  which  assist  in  the  several  movements  of  the  leg 
and  foot. 

The  Muscles  of  the  Foot. — The  muscles  of  the  foot 
are  the  following:  The  extensor  brevis  digitorum,  dorsal 
interossei,  abductor  hallucis,  abductor  minimi  digiti, 
flexor  brevis  digitorum,  flexor  accessorius,  lumbricales, 
flexor  brevis  hallucis,  adductor  transversus  hallucis, 
flexor  brevis  minimi  digiti,  transversus  pedis,  and  plantar 
interossei. 

While  lan  accurate  knowledge  of  the  exact  location  of 
each  of  the  muscles  of  the  foot  is  not  an  absolute  requisite, 
the  nurse  should,  by  reference  to  the  illustrations,  seek 
to  familiarize  herself  with  their  names  and  their  general 
location. 

The  anterior  annular  ligament  consists  of  an  upper 
vertical  portion,  which  binds  down  the  tendons  as  they 
descend  downward  to  their  several  attachments  (without 
this  no  power  would  be  obtained)  and  a  horizontal  portion. 
This,  with  the  internal  and  external  annular  ligaments, 
supports  all  the  tendons,  assisted  by  the  fascia  of  the  parts. 

MUSCLES   OF    THE   PERINEUM 

The  perineum  is  the  anterior  portion  of  the  outlet  of 
the  pelvis.  It  is  the  space  that  lies  between  the  anus  and 
the  genital  organs.  The  muscles  of  this  region  are  divided 
into  two  groups — those  that  control  the  organs  of  genera- 
tion and  those  governing  the  urethra  and  the  terminal 
portion  of  the  rectum. 

In  the  male  the  muscles  of  this  region  are :  The  acceler- 
ator urinae,  erector  penis,  transversus  perinei,  compressor 
urethrae,  sphincter  ani,  levator  ani,  and  coccygeus. 


THE  MUSCULAR  SYSTEM  85 

In  the  female  the  muscles,  while  similar,  are  somewhat 

smaller  than  in  the  rfiale,  and  receive  the  following  names : 

Constrictor  vaginae,  erector  clitoridis,  transversus  perinei, 

compressor  urethrae,  sphincter  ani,  levator  ani,  and  coccy- 

geus. 

REVIEW    QUESTIONS 

What  are  muscles? 

What  peculiar  property  do  muscles  possess? 

What  is  understood  by  origin  and  insertion? 

How  are  muscles  divided  for  purposes  of  description? 

How  many  muscles  are  there  in  the  body? 

What  is  a  sheath? 

How  are  muscles  attached  to  the  skeleton? 

What  two  kinds  of  muscular  tissue  have  we  in  the  body? 

What  muscle  covers  the  upper  part  of  the  head? 

How  many  muscles  have  we  in  the  auricular  region?     Name  them. 

What  muscles  are  in  the  palpebral  region? 

Name  the  several  muscles  of  the  orbital  region. 

How  many  pairs  of  muscles  are  there  in  the  nasal  region? 

What  do  you  understand  by  the  superior  maxillary  region? 

What  peculiar  action  have  the  muscles  of  this  region? 

What  muscles  have  we  in  the  inferior  maxillary  region?  Their 
action? 

What  important  muscles  have  we  in  the  intermaxillary  region? 

State  the  action  of  the  several  muscles  in  the  temporomaxillary 
region. 

How  many  muscles  are  there  in  the  pterygomaxillary  region? 

What  are  the  three  large  muscles  of  the  neck? 

What  action  has  the  digastric  muscle? 

What  are  the  several  functions  performed  by  muscles  of  the  palate 
region? 

What  is  the  pharynx? 

What  muscle  elevates  the  pharynx? 

What  function  do  the  pharyngeal  muscles  control? 

What  muscles  control  the  movements  of  the  head? 

Into  how  many  layers  are  the  muscles  of  the  back  divided? 

Name  two  of  the  superficial  muscles  of  the  back,  and  give  their  action. 

Name  the  muscles  of  the  abdomen. 

What  do  you  understand  by  the  linea  alba? 

What  important  functions  do  the  abdominal  muscles  assist  in  per- 
forming? 


S6        ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

Name  three  important  muscles  of  the  diaphragmatic  region. 
State  the  function  of  the  several  muscles  just  described. 
What  are  the  important  muscles  of  the  chest? 
What  function  do  they  assist  in  performing? 
What  muscle  forms  the  convexity  of  the  shoulder? 
What  are  the  groups  of  muscles  in  the  forearm? 
How  do  the  muscles  of  the  forearm  become  inserted? 
What  are  fasciae?     Explain  their  function. 
Name  the  important  muscles  of  the  iliac  region. 
What  is  the  longest  muscle  of  the  body?     Where  is  it  located? 
Name  three  muscles  of  the  gluteal  region. 
What  muscle  in  this  region  arises  by  three  digitations? 
How  many  muscles  are  there  in  the  leg? 
What  muscle  forms  the  calf  of  the  leg? 
What  is  the  function  of  the  anterior  annular  ligament? 
What  is  the  perineum,  and  how  many  groups  of  muscles  are  there  in 
this  region? 


CHAPTER    III 
THE  CIRCULATORY  OR  VASCULAR  SYSTEM 

The  organs  of  the  circulatory  or  vascular  system  are 
the  heart,  the  arteries,  the  veins,  and  all  structures  con- 
cerned in  the  propulsion  or  onward  movement  of  the  blood. 

Circulation  of  the  Blood. — The  heart  is  the  central 
station  to  which  the  blood  is  constantly  returned,  and  from 
which  it  is  as  constantly  distributed  to  all  parts  of  the 
body.  In  making  one  complete  revolution  of  the  body  the 
blood  passes  twice  through  this  organ,  making  its  circuit 
in  the  following  manner: 

As  it  returns  from  all  parts  of  the  system,  the  blood  is 
emptied  into  the  right  auricle  of  the  heart  by  what  is 
termed  the  ascending  and  the  descending  vena  cava;  thence 
it  passes  into  the  right  ventricle,  the  contraction  of  the 
heart  propelling  it  through  the  pulmonary  artery  into  the 
lungs.  From  this  point  the  blood,  oxygenated  by  its 
passage  through  the  lungs,  again  returns  through  the  four 
pulmonary  veins  (this  is  the  only  instance  in  the  adult 
circulation  where  the  veins  carry  arterial  blood)  into  the 
left  auricle,  passing  thence  into  the  left  ventricle;  from 
which,  by  the  contraction  of  the  heart,  it  is  propelled 
through  the  aorta  and  its  numerous  branches  and  dis- 
tributed to  every  part  of  the  body. 

THE   HEART 

The  heart  is  a  hollow,  muscular,  pear-shaped  organ, 
placed  obliquely  between  the  lungs.     It  is  nearer  the 

87 


88         ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

left  than  the  right  side  of  the  thorax,  its  base  pointing  up- 
ward and  its  apex  downward  toward  the  left  side.  It  is 
a  strong  body,  being  made  up  of  involuntary  muscular 
tissue,  which  is  known  as  the  myocardium.  It  is  enclosed 
in  the  pericardium,  a  loose  sac  that  also  contains  a  serous 
lubricating  fluid.  The  heart  is  commonly  regarded  as  the 
starting-point  of  the  blood  in  its  course  through  the  body; 
from  this  point  the  blood  is  propelled,  through  the  arteries, 
to  every  part  of  the  system. 


Fig.  45- — Orifices  of  the  heart,  seen  from  above,  both  the  auricles  and 
the  great  vessels  being  removed:  PA,  Pulmonary  artery  and  its  semilunar 
valves;  Ao,  aorta  and  its  valves;  RAV,  tricuspid,  and  LAV,  bicuspid 
valves;  mv,  segments  of  mitral  valve;  Iv,  segment  of  tricuspid  valve 
(Huxley). 

Cavities  of  the  Heart.— The  heart  is  divided  into 
two  parts — the  right  and  the  left  heart.  These  are  fur- 
ther divided  into  four  distinct  cavities,  called  respectively 
the  right  and  the  left  ventricle  and  the  right  and  the  left 
auricle.  By  referring  to  the  illustration  (Fig.  48)  it  will 
be  seen  that  the  auricles  are  the  upper  cavities  and  the 
ventricles  the  lower. 

The  cavities  of  the  heart  are  lined  by  a  delicate,  smooth 
membrane,  the  endocardium,  which  is  continuous  with  the 
intima  or  innermost  coat  of  the  great  blood-vessels. 


THE   CIRCULATORY  OR    VASCULAR   SYSTEM       89 

The  right  auricle  is  a  little  larger  than  the  left,  its  walls 
are  somewhat  thinner,  and  its  cavity  is  capable  of  contain- 
ing about  2  ounces.  The  following  openings  are  found  in 
the  right  auricle:  the  superior  vena  cava,  inferior  vena 
cava,  coronary  sinus,  foramina  Thebesii. 

The  right  ventricle  is  pyramidal  in  form,  and  extends 
from  the  right  auricle  to  near  the  apex  of  the  heart. 
Its  anterior  or  upper  surface  is  rounded  and  convex,  and 
forms  the  larger  part  of  the  front  of  the  heart.  The  right 
ventricle  is  provided  with  the  opening  of  the  pulmonary 
artery,  and  contains  upon  its  interior  the  following  valves : 
the  tricuspid  and  semilunar,  the  latter  guarding  the 
pulmonary  artery  and  the  former  the  opening  between  the 
auricle  and  ventricle. 

The  left  auricle  resembles  the  right  in  having  a  principle 
cavity  and  an  appendix,  but  its  walls  are  thicker,  measur- 
ing about  one  and  one-half  lines.  It  contains  openings  for 
the  pulmonary  veins,  four  in  number,  two  emptying  into 
the  right  and  two  into  the  left  side  of  the  auricle ;  frequently 
the  latter  terminate  by  one  common  opening. 

The  opening  between  the  ventricle  and  auricle  is  pro- 
vided with  the  bicuspid  or  mitral  valves. 

The  left  ventricle  is  longer  than  the  right,  and  more 
conical  in  shape.  It  forms  a  small  part  of  the  left  side  of 
the  anterior  surface.  It  forms  the  apex  of  the  heart  from 
its  projection  beyond  the  right  ventricle.  Its  walls  are 
much  thicker  than  those  of  the  right  side,  the  proportion 
being  3  to  i .  It  is  thinner  at  the  apex,  and  gradually  gets 
thinner  at  the  base.  It  is  provided  with  the  mitral  valves 
and  semilunar  valves,  the  former  making  a  division  be- 
tween the  auricle  and  ventricle  during  contraction  of  the 
ventricle,  and  the  latter  guarding  the  aortic  orifice.  The 
aortic  opening  is  to  the  right  side. 

The  Valves. — On  the  right  side,  the  valve  which  con- 
trols the  opening  from  the  right  auricle  to  the  right  ven- 


90 


ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 


tricle  is  known  as  the  tricuspid  valve.  It  is  composed  of 
three  triangular  segments,  made  up  of  a  dupHcation  of  the 
endocardium,  and  continuous  with  fine  cords  called  the 
cordae  tendineae,  which  close  the  aperture.  The  valve 
guarding  the  left  side  is  composed  of  two  irregular  seg- 
ments, and  is  called  the  bicuspid  or  mitral  valve.  If  these 
valves  were  to  become  diseased,  there  would  be  a  re- 


FlG.  46. — The  heart  (Stoney). 


gurgitation  of  blood  into  the  auricle  (this  will  be  clear  to 
you  if  you  will  recollect  the  manner  in  which  the  blood 
passes  through  the  heart,  as  previously  explained).  When 
healthy,  the  valves  close  accurately  and  form  a  complete 
partition  between  the  auricle  and  the  ventricle,  and  the 
blood  is  forced  on  through  the  large  arteries. 

Each  auricle  is  provided  with  openings  for  the  arteries 
and   veins   that   enter   from   the   circulation.     The   left 


THE   CIRCULATORY  OR    VASCULAR  SYSTEM       9 1 

ventricle  gives  off  the  aorta,  the  largest  arterial  structure 
in  the  body.  The  orifice  of  the  aortic  opening  is  guarded 
by  valves,  called  the  semilunar;  in  the  fetus  two  are 
anterior  and  one  posterior,  but  in  the  adult  one  is  anterior 
and  two  are  posterior,  right  and  left. 


Fig.  47. — Left  auricle  and  ventricle,  opened  and  part  of  their  walls  re- 
moved to  show  their  cavities  :  i,  Right  pulmonary  vein  cut  short ;  i',  cavity 
of  left  auricle;  3,  3',  thick  wall  of  left  ventricle;  4,  portion  of  the  same 
with  papillary  muscle  attached;  5,  the  other  papillary  muscles;  6,  6',  the 
segments  of  the  mitral  valve ;  7,  in  aorta  is  placed  over  the  semilunar 
valves ;  8,  pulmonary  artery ;  10,  aorta  and  its  branches  (Allen  Thomson). 


Contraction  of  the  ventricles  takes  place,  at  the  same 
time  forcing  the  blood  to  the  lungs  from  the  right  heart, 
through  the  pulmonary  artery,  and  to  the  body  generally 
from  the  left  heart,  through  the  aorta. 

The  aorta,  rising  from  the  left  ventricle,  immediately 
gives  off,  from  its  ascending  portion,  the  two  coronary 


92 


ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 


arteries;  at  its  arch  it  furnishes  the  left  carotid  and  left 
subclavian  on  one  side,  and  on  the  other  only  one,  the  in- 
nominate, which  is  larger  than  either  of  those  on  the  left 
side.  In  the  thorax  the  aorta  gives  off  the  bronchial 
arteries — one  on  each  side;  these  nourish  the  lungs.  It 
also  gives  off  at  this  portion  the  esophageal,  mediastinal, 


Fig.  48. — Normal  blood-currents  in  the  heart  and  relative  position  of  the 
ventricles,  auricles,  and  great  vessels :  IVC,  Inferior  vena  cava;  SVC,  su- 
perior vena  cava;  RA,  right  auricle;  TV,  tricuspid  valves;  RV,  right  ven- 
tricle ;  P,  pulmonary  valves  ;  PA,  pulmonary  artery  ;  Pv,  pulmonary  veins; 
LA,  left  auricle;  MV,  mitral  valves;  LV,  left  ventricle;  A,  aortic  valves; 
Aa,  arch  of  aorta  (Page). 


and  intercostal  arteries.  From  the  abdominal  portion  it 
gives  off  the  celi^^axis  with  its  three  branches,  the  gas- 
tric, hepatic,  and  splenic  arteries;  the  superior  and  m^ 
feri(3r  mesenteric,  suprarenal,  renal,  spermatic  (or  ovarian), 
lumbar,  and  middle  sacraFarteries.  At  the  left  side  of  the 
fourth  lumbar  ver^bra  the  aorta  bifurcates  into  two 
common  iliacs,  which  each  again  divide  into  the  internal 


THE   CIRCULATORY  OR    VASCULAR  SYSTEM       93 

and  the  external  iliac,  the  internal  supplying  the  pelvic 
tissues  and  the  external  the  lower  extremities. 

The  Heart=beat.— The  heart  in  the  healthy  adult  beats 
from  60  to  80  times  in  a  minute ;  in  children  and  infants 
the  beat  is  more  frequent,  varying  from  100  to  150  times 
in  a  minute. 

Arteries  are  all  characterized  by  a  vibrating  action, 
called  pulsation,  which  corresponds  to  the  working  of  the 
heart.  This  pulsation  is  in  part  dependent  upon  the 
action  of  the  latter  organ,  but  partly  also  on  a  similar 
power  of  contraction  possessed  by  the  arteries  themselves. 

The  motion  of  the  blood  in  the  arteries  is  always  in  a 
direction  away  from  the  heart,  and  this  fluid  is  propelled 
in  these  vessels  by  the  pulsating  force  just  described. 

The  systemic  circulation  is  made  up  of  two  chief  divis- 
ions— the  arterial  and  the  venous  systems.  In  addition 
to  these,  two  subsidiary  systems  are  described — the  pul- 
monary and  the  portal.  We  will  describe  first  the  arterial 
system,  prefacing  our  remarks  by  a  brief  description  of  the 
arteries  themselves. 

This  diagram,  taken  from  Gray,  shows  the  various 
parts  and  openings  of  the  heart.  The  nurse  will  do  well  to 
make  herself  familiar  with  their  names,  and,  by  frequent 
reference  to  the  illustrations,  seek  to  learn  their  location: 


Openings 
in  the 
heart: 


Superior  vena  cava. 
Inferior  vena  cava. 
Coronary  sinus. 
Foramina  Thebesii. 
Auriculoventricular  opening 
Pulmonary  artery. 
Pulmonary  veins. 
Aorta. 
Auriculoventricular  (right). 


Relics  of  fetal 
structures : 


Annulus  ovalis. 
Fossa  ovalis.   • 


Valves  {right  side)  .■r'''''''^'^ 


Musculi  pectinati. 


Valves  : 


(  Eustachian. 
I  Coronary. 


i  Semilunar. 


Valves  {left  side)  : 


f  Mitral. 
I  Semilunar. 


94        ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 


THE  ARTERIAL  SYSTEM 
The  arteries  are  the  cyUndric  tubes  that  convey  the 
blood  from  the  ventricles  of  the  heart  to  every  part  of  the 
body.  They  are  capable  of  preserving  their  form  at  all 
times.  In  ancient  times,  the  arteries  being  found  empty 
after  death  and  still  preserving  their  cylindric  form,  were 
believed  to  contain  air.  This  theory  was  held  until  the 
time  of  Harvey,  who  discovered  the  circulation  of  the 

blood  and  presented  it  to 
the  world  as  we  now  teach 
it. 

As  has  been  said,  the 
main  artery  of  the  body 
is  the  aorta;  from  this  all 
the  arterial  tissues  derive 
their  origin.  This  will  be 
described  further  on.  The 
communications  of  arteries 
are  numerous.  They  do 
not  terminate  in  veins,  but 
are  connected  with  the  lat- 
ter by  an  intermediate  sys- 
tem of  vessels,  called  capil- 
laries (from  capillus,  a  hair). 
So  numerous  are  these  vessels  that  the  slightest  injury, 
such  as  a  needle-prick,  implicates  many  of  these  vessels 
and  they  bleed  profusely. 

The  capillaries,  as  has  been  said,  are  the  intermedi- 
ate vessels  between  the  arteries  and  veins.  It  is  in  these 
vessels  that  the  most  important  functions  or  changes  of  the 
blood  occur — the  change  from  arterial  to  venous  blood. 
Here  the  phenomena  of  oxidation  and  calorification  take 
place,  and  it  is  from  this  system  that  the  endless  variety 
of  materials  is  supplied  to  the  tissues  of  the  body  for 
nutrition  and  for  glandular  secretions. 


Fig. 


49. — Diagram    of    capillaries 

(Morrow). 


THE    CIRCULATORY  OR    VASCULAR   SYSTEM       95 

The  Structure  of  Arteries. — The  arteries  are  com- 
posed of  three  coats — an  external,  a  middle,  and  an 
internal. 

The  external  coat  is  firm  and  strong,  and  is  made  up  of 
elastic  and  areolar  tissues  containing  longitudinal  and 
oblique  fibers.  It  is  of  tougher  texture  than  the  middle 
coat. 

The  middle  coat  is  a  thick,  circular  coat  which  contains 
muscular  tissue,  the  fibers  of  which  are  arranged  in  rings 
that  vary  in  number  according  to  the  size  of  the  artery. 
They  contain  some  elastic  tissue,  but  this  is  lost  in  the 
smaller  arteries;  in  the  larger  ones  the  elastic  tissue  is 
blended  with  the  areolar  tissue. 


Endothelium  of  the 

intima. 
Intima. 

Media. 


A  dven  titia   with 
non-striated  mus- 
cle-fibers in  cross- 
section. 


Fig.  50. — Section  through  human  artery,  one  of  the  smaller  of  the  medium- 
sized  (X  640)  (Bohm  and  Davidoff). 


The  internal  coat  is  a  thin,  endothelial  layer  on  the  in- 
side, and  has  an  elastic  exterior.  In  the  large  arteries 
there  is  an  intermediate  layer  composed  of  areolar  tissue. 

From  what  has  been  said  it  will  be  seen  that,  considered 
from  without  inward,  the  external  coat  consists  of  areolar 
and  elastic  tissues;  the  middle  coat,  of  smooth  muscular 
fiber  and  areolar  and  elastic  tissues;  the  internal  coat,  of 
elastic  tissue  and  endothelium. 

The  walls  of  the  capillaries  are  composed  of  only  one 
coat,  which  is  thin,  transparent,  and  composed  of  tissue 
of  light  structure,  which  is  lost  in  the  elastic  membrane  of 


96        ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

the  internal  coat  of  the  arteries  and  in  the  middle  coat  of 
the  veins.  The  capillaries  form  plexuses,  which  are  very 
abuadant,  especially  in  the  lungs,  liver,  kidneys,  and  other 
secreting  glands.  The  skin  and  mucous  membranes  con- 
tribute very  freely  to  this  system.  In  the  bones  the  capil- 
laries are  larger,  but  not  so  numerous. 

The  arteries  are  invested  in  a  loose  areolofibrous  tissue 
called  a  sheath.  This  is  considered  an  important  structure 
in  surgical  operations;  it  also  contains  the  accompanying 
veins,  and  at  times  a  nerve. 

The  coats  of  the  arteries  are  supplied  with  blood  from 
the  small  branches  which  run  in  line  with  such  structures. 
These  are  the  vasa  vasorum,  or  nutrient  vessels,  and  are 
distributed  to  the  external  coat.  The  small  veins  which 
return  the  blood  from  the  capillaries  open  into  the  small 
veins  accompanying  the  arteries.  The  arteries  are  also 
supplied  with  nerves. 

THE   AORTA 

The  aorta  is  the  largest  arterial  trunk  in  the  body.  It 
arises  from  the  base  of  the  left  ventricle  and  middle  of  the 
heart,  and  at  its  beginning  presents  an  enlargement,  called 
the  bulbus  aortse,  which  contains  the  semilunar 
valves.  These  valves  are  three  in  number,  and  prevent 
the  blood  from  re-entering  the  left  ventricle,  whence  it 
comes. 

After  leaving  the  left  ventricle  the  aorta  passes  upward, 
backward,  and  over  the  root  of  the  left  lung  to  form  the 
arch.  On  the  right  side  this  arch  gives  off  a  single  branch 
about  2  inches  in  length ;  this  is  the  innominate  artery, 
which  subdivides  into  the  right  common  carotid  and  the 
right  subclavian.  On  the  left  side  of  the  arch  the  left 
common  carotid  and  left  subclavian  are  given  off  sepa- 
rately. 

From  the  arch  the  aorta  descends  through  the  chest  as 


THE   CIRCULATORY  OR    VASCULAR  SYSTEM       97 

the  thoracic  aorta;  after  passing  through  the  diaphragm 
it  is  termed  the  abdominal  aorta. 

The  first  or  ascending  portion  of  the  aorta  is  about  2  J 
inches  in  length,  and  is  contained  within  the  pericardiumc 
Anteriorly,  it  is  in  relation  with  the  pulmonary  artery ;  on 
the  left  side,  with  the  left  auricle  and  pulmonary  artery;  on 
the  right  side,  with  the  right  auricle  and  superior  vena  cava; 
and  behind,  with  the  right  pulmonary  artery  and  veins. 

The  second  or  transverse  portion  gives  off  the  innominate 
artery,  left  common  carotid,  and  left  subclavian  arteries. 
It  is  in  relation  behind  with  the  left  recurrent  nerve,  tra- 
chea, esophagus,  thoracic  duct,  and  nerves  of  the  cardiac 
plexus;  in  front,  with  the  left  phrenic,  left  superior  car- 
diac, and  left  pneumogastric  nerves. 

The  third  or  descending  portion  of  the  arch  lies  adjacent 
to  the  third  dorsal  vertebra,  and  is  covered  with  a  portion 
of  the  pleura. 

The  descending  aorta  proper  is  divided  into  two  great 
portions,  named  the  thoracic  and  the  abdominal  aorta. 

The  thoracic  aorta  takes  its  origin  at  the  lower  border 
and  to  the  left  of  the  third  dorsal  vertebra,  curves  forward 
to  the  right,  runs  downward  on  the  median  line  of  the 
vertebral  column,  and  passes  through  the  aortic  opening 
in  the  diaphragm.  Relations:  behind,  with  the  vertebral 
column  and  vena  azygos  minor;  anteriorly,  with  the 
esophagus  and  left  pneumogastric  nerve;  on  the  left,  with 
the  pleura;  on  the  right,  with  the  thoracic  duct. 

The  abdominal  portion  (see  Fig.  56)  enters  through  the 
opening  in  the  diaphragm,  proceeds  downward  in  line  with 
the  vertebral  column,  slightly  to  the  left,  and  extends  to 
the  fourth  lumbar  vertebra,  where  it  divides  into  the  two 
common  iliac  arteries.  Relations:  in  front,  with  the  left 
renal  and  splenic  veins,  pancreas,  transverse  duodenum, 
and  mesentery;  behind,  with  the  thoracic  duct,  receptacu- 
lum  chyli,  and  left  lumbar  veins ;  on  the  left,  with  the  left 
7 


98         ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 


semilunar  ganglion,  suprarenal  capsule,  and  sympathetic 
nerve ;  on  the  right,  with  the  right  semilunar  ganglion  and 
the  commencement  of  the  vena  azygos  major. 

The  branches  given  off  from  the  aorta  are  as  follows : 


Arch 


Innominate  : 


Ascending  portion.     Coronary,  right  and  left. 

f  Right  common  carotid. 
\  Right  subclavian. 
Left  common  carotid. 
Left  subclavian. 


Transverse  portion. 


Thoracic  aorta , 


Abdominal  aorta . 


C  Pericardiac. 
I   Bronchial. 
Esophageal. 
Posterior  mediastinal. 
Intercostal. 

r  Gastric. 
Celiac  axis  :  -l   Hepatic. 
[  Splenic. 
Inferior  phrenic  (2)  suprarenal. 

Inferior  pancreatico- 
duodenal. 
Ileocolic. 
Colica  dextra. 
Vasa  intestini  tenuis. 
.  Colica  media, 
f  Colica  sinistra. 
-!   Sigmoid. 
[  Superior  hemorrhoidal. 


Superior  mesenteric  : 


Inferior  mesenteric 


Middle  suprarenal. 

Renal. 

Spermatic  (in  female,  ovarian). 

Lumbar. 

Dorsal. 

Middle  sacral. 


The  coronary  artery  arises  from  the  aortic  sinuses 
at  the  commencement  of  the  ascending  portion  at  the 
arch,  immediately  above  the  margin  of  the  semilunar 
valves,  dividing  into  the  right  and  the  left  coronary  arteries, 
which  inosculate  with  each  other  and  supply  the  substance 


THE   CIRCULATORY  OR    VASCULAR   SYSTEM       99 

of  the  heart  with  nutrition.  These  arteries  encircle  the 
heart  in  both  the  horizontal  and  the  vertical  directions. 

The  innominate  artery  is  the  first  and  largest 
trunk  given  off  from  the  arch  of  the  aorta;  it  is  about  i^ 
inches  in  length,  and  ascends  obliquely  toward  the  right 
sternoclavicular  articulation,  where  it  divides  into  the 
right  common  carotid  and  right  subclavian  arteries.  It 
occasionally  gives  off  a  small  branch  to  the  thyroid  gland. 

The  Common  Carotid  Arteries.— The  right  arises 
from  the  bifurcation  of  the  innominate  artery,  opposite 
the  right  sternoclavicular  articulation.  The  lejt  ascends 
from  the  arch  of  the  aorta.  The  right  is  shorter  than  the 
left,  more  anterior,  and  somewhat  larger. 

The  right  common  carotid  ascends  the  neck  perpendicu- 
larly by  the  side  of  the  trachea  and  larynx,  from  behind  the 
right  sternoclavicular  articulation  to  the  level  of  the  upper 
border  of  the  thyroid  cartilage,  where  it  divides  into  the 
right  external  and  internal  carotids. 

The  left  common  carotid  ascends  from  the  aortic  arch 
obliquely  outward  to  the  side  of  the  neck,  and  upward  by 
the  side  of  the  trachea  and  esophagus  to  the  upper  border 
of  the  thyroid  cartilage,  where  it  divides  into  the  left 
external  and  internal  carotids. 

The  external  carotid  ascends  perpendicularly  be- 
tween the  lower  jaw  and  auditory  meatus,  where  it  divides 
into  two  terminal  branches,  the  temporal  and  the  internal 
maxillary ;  it  gives  off  the  following  branches : 

Anterior.  Posterior. 

Superior  thyroid.  Occipital. 

Lingual.  Posterior  auricular. 
Facial. 

Ascending.  Terminal. 

Ascending  pharyngeal.  Superficial  temporal. 

>,,.,,     ,    Internal  iTiaxilkry .  ^  ^  ^ 


lOO      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

The  external  branches  arise  from  the  commencement 
of  the  external  carotid,  within  a  short  distance  of  each 
other.  The  lingual  and  facial  sometimes  bifurcate  from 
the  common  carotid. 

The  superior  th3nroid  artery  arises  from  the  external 
carotid;  and  is  distributed  to  the  thyroid  gland;  it  anasto- 
moses with  the  vessel  of  the  opposite  side,  and  gives  off 
the  following  branches: 

Hyoid.  Cricothyroid. 

Superior  laryngeal.  Muscular. 

The  lingual  artery  ascends  obliquely  from  its  origin 
parallel  with  the  hyoid  bone,  and  directly  forward,  taking 
the  name  ranine  artery,  where  it  inosculates  with  the 
opposite  side;  it  gives  off  the  following  branches:  hyoid, 
dorsalis  linguae,  sublingual,  and  ranine. 

The  facial  artery  arises  immediately  above  the  lingual, 
and  a  short  distance  above  the  great  cornu  of  the  hyoid 
bone.  It  is  embedded  in  the  submaxillary  gland,  curves 
around  the  lower  jaw  at  the  inferior  angle  of  the  masseter 
muscle,  ascends  to  the  angle  of  the  mouth,  and  terminates 
at  the  inner  angle  of  the  eye,  under  the  name  of  the  angular 
artery. 

The  facial  artery  is  tortuous  in  its  course  over  the  buc- 
cinator muscle,  to  accommodate  itself  to  the  movements 
of  the  jaw.  The  branches  that  are  given  off  are  divided 
into  two  sets — those  given  off  below  the  jaw  (cervical) 
and  the  facial ;  these  are  as  follows : 

Below  the  jaw:  On  the  face: 

Inferior  palatine.  Buccal  (muscular). 

Tonsillar.  Inferior  labial. 

Submaxillar.  Inferior  coronary. 

Submental.  Superior  coronary.    . 

Muscular.  Lateralis  nasi. 


THE   CIRCULATORY  OR    VASCULAR  SYSTEM     1 01 

In  its  distribution  this  artery  sometimes  terminates  at 
the  angle  of  the  mouth  or  nose,  at  the  ala,  and  its  inoscu- 
lations are  numerous. 

The  occipital  artery,  one  of  the  branches  of  the  external 
carotid,  arises  opposite  the  styloid  process  of  the  temporal 
bone,  and  ascends  beneath  the  parotid  gland  and  under 


Fig.  51. — Facial  and  temporal  arteries:  Ce,  External  carotid;  tsu,  su- 
perior thyroid  ;  Is,  superior  laryngeal ;  ct,  cricothyroid ;  hy,  hyoid  branch 
of  lingual ;  dl,  dorsal  of  tongue  ;  s,  sublingual ;  me,  facial ;  smt,  submental ; 
a,  angular;  Ibi,  inferior  labial ;  lbs,  coronary  of  upper  Up ;  su,  artery  of  nasal 
septum  ;  sc,  sc' ,  sternomastoids  ;  ap,  posterior  auricular  ;  st,  stylomastoids  ; 
pda,  ascending  pharyngeal ;  mi,  internal  maxillary  ;  tps,  superficial  tem- 
poral ;  tf,  transyerse  facial ;  tm,  middle  temporal ;  2,  external  supra-orbital ; 
/  frontal;  so,  supra- o rb i tal ;  la,  lacrimal;  n,  nasal;  *,  parotid  branches  of 
'external  carotid  (after  Henlc). 

the  sternomastoid  muscle,  passing  along  to  the  occipital 
groove  in  the  mastoid  portion  of  the  temporal  bone;  it 
then  ascends  and  is  distributed  to  the  back  part  of  the 
head.  It  furnishes  the  following  branches:  muscular 
(supplying  the  sternomastoid,  digastric,  stylohyoid), 
auricular,  meningeal,  and  arteria  princeps  cervicis. 


I02      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

The  stemomastoid  {superficial  descending  branch)  is  dis- 
tributed to  the  stemomastoid  muscle  and  lymphatic 
glands. 

The  posterior  auricular  artery  arises  from  the  external 
carotid  opposite  the  styloid  process  of  the  temporal  bone. 
It  is  distributed  to  the  external  ear  and  side  of  the  head; 
it  anastomoses  with  the  occipital  and  temporal  arteries. 
It  gives  off  several  branches  to  the  muscles  and  furnishes 
a  branch  to  the  parotid  gland,  as  well  as  branches  to  the 
mastoid  cells  of  the  temporal  bone  and  tympanum  of  the 
ear. 

The  ascending  pharyngeal  artery  is  the  smallest  of  the 
branches  of  the  external  carotid.  Its  branches  are  divided 
into  three  sets — meningeal,  to  the  dura  mater;  pharyn- 
geal, to  the  pharynx,  tonsils,  soft  palate;  and  a  preverte- 
bral branch,  to  the  posterior  part  of  the  throat. 

The  parotid  arteries  give  off  several  branches  that 
supply  the  parotid  gland;  they  also  supply  the  integu- 
ment of  the  face  and  the  masse ter  muscle. 

The  temporal  artery  {superficial)  is  one  of  the  terminal 
branches  of  the  external  carotid,  and  divides  into  anterior 
and  posterior  branches.  The  anterior  branch  runs  for- 
ward and  is  distributed  to  the  temple;  the  posterior 
anastomoses  with  the  posterior  auricular,  with  the  occip- 
ital, and  with  its  fellow  on  the  opposite  side.  The 
branches  given  off  from  this  artery  are:  the  anterior 
auricular,  which  are  distributed  to  the  pinna  of  the  ear; 
an  orbital  branch,  which  unites  with  the  ophthalmic 
artery;  the  transverse  facial,  which  arises  from  the  tem- 
poral and  unites  with  the  facial  and  infra-orbital  arteries; 
and  the  middle  temporal,  which  supplies  the  temporal 
muscle,  associated  with  the  deep  temporal  artery. 

The  internal  maxillary  artery  is  the  larger  terminal 
branch  of  the  external  carotid ;  it  passes  inward  in  the  deep 
structure  of  the  face,  at  the  inner  side  of  the  condyle  of 


THE   CIRCULATORY  OR    VASCULAR   SYSTEM      IO3 

the  lower  jaw,  and  divides  into  three  portions — the  max- 
illary, the  pterygoid,  and  the  sphenomaxillary;  these  are 
subdivided  into  the  following  branches  (see  Fig.  51): 


Maxillary. 

Pterygoid. 

Tympanic. 

Inferior  dental  : 

Middle  meningeal. 
Small  meningeal. 

r  Mylohyoid. 
\  Incisor. 
(  Mental. 

Deep  temporal  J^^"^'^"^^"- 
Pterygoid.             ^Posterior. 

Masseteric. 
Buccal. 

Posterior  dental. 
Infra-orbital. 

Sphenomaxillary 
Sphenopalatine. 
Pterygopalatine. 

Posterior  palatine. 
Vidian. 

The  Internal  Carotid  Artery. — This  arises  from 
the  common  carotid,  curves  backward  and  outward,  and 
ascends  upward  by  the  side  of  the  pharynx  to  the  carotid 
foramen  in  the  petrous  portion  of  the  temporal  bone.  It 
then  passes  inward  along  the  carotid  canal,  where  it  pierces 
the  dura  mater  and  divides  into  three  terminal  branches. 
This  artery  makes  many  curves,  which  may  be  seen  at  the 
cervical  portion,  at  the  base  of  the  skull.  It  divides  into 
the  anterior  and  middle  cerebral  arteries.  The  cervical 
portion  of  the  artery  gives  off  no  branches.  Within  the 
skull  the  following  branches  are  given  off: 


Tympanic. 
Arteriae  receptaculi. 
Anterior  meningeal. 
Ophthalmic. 


Anterior  cerebral. 
Middle  cerebral. 
Posterior  communicating. 
Anterior  choroid. 


I 


The  tjrmpanic  is  a  small  branch  given  off  in  the  carotid 
canal;  it  penetrates  the  tympanum  and  unites  with  the 
tympanic  branch  of  the  internal  maxillary  and  the  stylo- 
mastoid arteries. 

The  arteriae  receptaculi  are  small  vessels  that  supply  the 


104      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 


cavernous  and  inferior  petrosal  sinuses,  pituitary  body, 
and  Gasserian  ganglion. 

The  anterior  meningeal  supplies  the  dura  mater  of  the 
anterior  fossa. 

The  ophthalmic  artery  arises  from  the  cavernous  por- 
tion, enters  the  orbit  by  the  optic  foramen,  dividing  at  the 
inner  angle  of  the  eye  into  two  terminal  divisions — the 
frontal  and  the  nasal — which  further  divide  into  the 
following  branches: 


Orbital. 


Lacrimal. 

Supra-orbital. 

Posterior  ethmoid. 

Anterior  ethmoid. 

Palpebral. 

Frontal. 

Nasal. 


Ocular . 


Muscular. 

Anterior  ciliary. 

Short  ciliary. 

Long  ciliary. 

Arteria  centralis  retinae. 


The  anterior  cerebral  artery  enters  the  longitudinal 
fissure  between  the  two  hemispheres  of  the  brain ;  it  gives 
branches  to  the  olfactory  and  optic  nerves.  The  two  arte- 
ries on  each  side  join,  shortly  after  origin,  by  a  short  anas- 
tomosing branch.  (See  chapter  on  the  Nervous  System 
for  a  more  complete  description  of  the  arteries  that  supply 
the  brain,  including  the  middle  cerebral,  posterior  com- 
municating, and  anterior  choroid.) 

The  Subclavian  Artery. — The  right  subclavian 
artery  takes  it  origin  from  the  innominate  artery,  opposite 
the  sternoclavicular  articulation;  the  left  arises  directly 
from  the  aorta.  At  the  lower  border  of  the  first  rib  it 
ceases  to  be  called  the  subclavian,  and  becomes  the  axil- 
lary. For  descriptive  purposes  the  artery  is  generally 
divided  into  three  sections.  This  division  is  necessary, 
owing  to  the  fact  that  there  is  a  difference  in  the  origin  of 
the  right  and  the  left  arterial  trunk;  it  follows,  therefore, 
that  there  is  a  marked  difference  in  the  first  part  of  the 
course  of  this  artery.    On  the  right,  the  first  portion  passes 


THE   CIRCULATORY  OR    VASCULAR  SYSTEM      105 

obliquely  upward  and  outward  to  the  inner  border  of  the 
scalenus  anticus  muscle;  on  the  left  side  it  passes  upward 
to  the  inner  border  (not  outward).  The  second  portion 
curves  outward  behind  the  same  muscle;  the  third  passes 
downward  and  outward  beneath  the  clavicle  to  the  lower 
border  of  the  first  rib,  where  it  becomes  the  axillary  artery. 


Fig. 52. — Subclavian  artery:  Ah,  Innomfnate;  Cc,  common  carotid;  5, 
subclavian  ;  v,  vertebral ;  ba,  basilar  ;  mmi,  internal  mammary  ;  es,  superior 
epigastric  ;  mp,  musculophrenic  ;  is,  superior  intercostal ;  cvp,  deep  cervical ; 
ti,  inferior  thyroid;  cva,  ascending  cervical;  cvs,  superficial  cervical 
suprascapular;  /^,  posterior  scapular  (after  Heiile). 


is. 


The  branches  which  this  important  artery  furnishes  are 


the  following : 


Vertebral. 
Internal  mammary. 

Thyroid  axis  : 

Superior  intercostal. 


Inferior  thyroid. 
Suprascapular. 
Transversalis  colli. 


I06      AXATOMY  AND   PHYSIOLOGY  FOR   NURSES 

The  vertebral  artery  is  the  first  and  largest  branch.  It 
arises  from  the  back  part  of  the  subclavian  artery,  passes 
upward  through  the  foramina  in  the  transverse  process  of 
the  upper  six  cervical  vertebra ;  it  turns  backward  around 
the  articulating  process  of  the  atlas,  after  which  it  enters 
the  skull  through  the  foramen  magnum.  The  two  ver- 
tebral arteries  unite  to  form  the  basilar  artery.  The 
branches  of  the  vertebral  may  be  divided  into  two  groups : 

Cervical  branches.  Cranial  branches. 

Lateral  spinal.  Posterior  meningeal. 

Muscular.  Anterior  spinal. 

Posterior  spinal. 

Postero-inferior  cerebellar. 

The  basilar  artery  is  situated  at  the  base  of  the  brain. 
It  runs  in  the  median  groove  of  the  pons  Varolii,  and  di- 
vides into  the  following  branches : 

Transverse.  Superior  cerebellar. 

Antero-inferior  cerebral.      Posterior  cerebral. 

The  internal  mammary  artery  arises  and  descends  within 
the  chest  from  the  under  side  of  the  subclavian,  alongside 
of  the  sternum,  upon  the  cartilages  of  the  ribs,  to  the 
sheath  of  the  rectus  muscle,  where  it  takes  the  name  of  the 
superior  epigastric;  the  continuation  of  this  vessel  joins  the 
epigastric  branch  of  the  external  iliac.  This  artery  is 
crossed  by  the  phrenic  nerve  just  as  it  enters  the  chest.  It 
distributes  to  the  muscles  of  the  abdominal  walls  and  gives 
off  several  branches,  which  are  as  follows: 

Comes  nervi  phrenici.  Anterior  intercostal. 

Mediastinal.  Perforating. 

Pericardiac.  Musculophrenic. 

Sternal.  Superior  epigastric. 


THE   CIRCULATORY  OR    VASCULAR   SYSTEM      lO/ 


The  thyroid  axis  is  a  short  trunk,  and  divides  into  three 
branches — the  inferior  thyroid,  suprascapular,  and  trans- 
versalis  colh. 

The  superior  intercostal  artery  arises  from  the  sub- 
clavian, and  gives  off  branches  to  the  intercostal  spaces  and 
to  the  muscles  of  the  dor- 
sal region;  it  runs  behind 
the  pleura  and  to  the  outer 
side  of  the  sympathetic 
nerve,  and  joins  the  in- 
tercostal branch  from  the 
aorta. 

The  profunda  cervicis  is 
a  branch  of  the  superior 
intercostal;  it  unites  with 
branches  from  the  occipital 
and  vertebral  arteries,  and 
supplies  the  several  mus- 
cles of  the  parts  through 
which  it  passes. 

The  Axillary  Artery. — 
We  will  now  consider  the 
axillary  artery  and  its 
branches.  This  artery  com- 
mences at  the  lower  border 
of  the  first  rib  and  extends 


Fig.  53. — Axillary  artery  and 
branches :  Ax,  Axillary  ;  B,  brachial ; 
ths,  superior  thoracic  ;  tka,  acromio- 
thoracic  ;  thl,  external  mammary  ; 
cha,  anterior  circumflex;  chp,  pos- 
terior circumflex;  ss,  subscapular; 
^j<:,  circumflex  of  scapula;  i,  sub- 
clavius  muscle  ;  2,  pectoralis  muscle  ; 
3,  serratus  magnus;  4,  latissimus 
dorsi ;  5,  teres  major;  6,  long  head 
of  triceps;  7,  deltoid;  8,  subscapular 
muscle;  9,  bicipital  groove  (after 
Henle). 


to  the  lower  border  of  the 

teres  major  muscle,  where  it  becomes  the  brachial. 

relations  are  as  follows : 


Its 


In  front. 
Pectoralis  major. 
Pectoralis  minor. 


Inner  side. 
First  intercostal  muscle. 
Serratus  magnus. 
Brachial  plexus. 
Axillary  vein. 


Outer  side. 
Brachial  plexus. 
Coracobrachialis. 


I08      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 
The  branches  are: 


Superior  thoracic. 
Acromial  thoracic. 
Long  thoracic. 


Thoracica  alaris. 
Subscapular. 
Anterior  circumflex. 


Posterior  circumflex. 


The  Brachial  Artery.— This  is  a  continuation  of  the 
axillary,  passing  down  the  inner  side  of  the  arm  to  a  little 


i; 


M 


Fig.  54. — Brachial  artery  and  branches :  B,  Brachial ;  R,  radial ;  U, 
ulnar ;  els,  deltoid  artery  ;  cli,  deep  radial ;  pb,  superior  profunda ;  cm,  arteria 
collateralis  media ;  cui,  anastomotic ;  rr,  anterior  radial  recurrent ;  ru,  an- 
terior ulnar  recurrent ;  ico,  common  interosseous  ;  ia,  anterior  interosseous ; 
ip,  posterior  interosseous ;  ir,  posterior  interosseous  recurrent ;  iar,  palmar 
anterior  interosseous;  iad,  dorsal  anterior  interosseous;  m,  median;  cvr, 
anterior  radiocarpal ;  cvu,  anterior  ulnocarpal ;  cdr,  posterior  radiocarpal ; 
cdu,  posterior  ulnocarpal ;  mdu,  posterior  ulnocarpal ;  mvs,  superficial  volar; 
mvp,  ulnar  part  of  deep  palmar  arch ;  dc,  first  palmar  digital  (after  Henle). 


THE   CIRCULATORY  OR    VASCULAR   SYSTEM      IO9 

below  the  bend  of  the  elbow,  where  it  divides  into  radial 
and  ulnar  arteries.      It  gives  off  the  following  branches: 

Superior  profunda. 
Nutrient. 

Inferior  profunda. 
Anastomotica  magna. 
Muscular. 

The  radial  artery  is  a  branch  of  the  brachial,  and 
appears  to  be  a  continuation  of  this  artery;  its  course  is 
along  the  radial  side  of  the  forearm  from  the  elbow  to  the 
wrist;  passing  backward  around  the  thumb,  it  runs  be- 


SJM,:       .\ 


Fig.  55. — Dorsal  arteries  of  hand :  cdr,  Eadial  posterior  carpal ;  cdu,  ulnar 
posterior  carpal;  mdr,  dorsales  poUicis ;  imd^,  imd%,  mrfa/dorsal  interossei  ; 
im-J*',  posterior  perforating;  dd,  dorsal  digital  (after  Henle). 


tween  the  heads  of  the  first  dorsal  interosseous  muscle 
into  the  palm  of  the  hand,  forming  the  deep  palmar 
arch. 

For  descriptive  purposes  this  artery  is  divided  into 
three  parts,  which  correspond  with  the  parts  which  it 


no      ANATOA/V  AND   PHYSIOLOGY  FOR   NURSES 


supplies,  viz.,  the  forearm,  the  wrist,  and  the  hand, 
divisions  are: 


Its 


Forearm. 
Radial  recurreTft. 
Muscular. 
Superficialis  volae. 
Anterior  C£ 


Wrist. 
Posterior  carpal. 
Metacarpal. 
Dorsales  pollicis. 
Dorsales  indicis. 


Hand. 
Princeps  pollicis. 
Radialis  indicis. 
Interosseous. 
Perforating. 
Palmar  recurrent. 


The  ulnar  artery  is  larger  than  the  radial,  and  runs 
obliquely  inward  to  the  middle  of  the  forearm ;  then  across 
the  annular  ligament  to  the  radial  side  and  to  the  palm, 
where  it  unites  with  the  superficialis  volae  or  radialis 
indicis  to  form  the  superficial  palmar  arch.  The  branches 
of  the  ulnar  artery  are  as  follows : 


Forearm. 
Anterior  ulnar  recurrent. 
Posterior  ulnar  recurrent. 
Interosseous  (anterior  and 

posterior). 
Muscular. 


Wrist. 
Anterior  carpal. 
Posterior  carpal. 


Hand. 
Communicating, 
Digital. 

Superficial  palmar  arch. 
Deep  palmar  arch. 


Having  considered  the  arterial  structure  of  the  upper 
portion  of  the  body,  we  will  now  describe  the  blood-supply 
of  the  trunk  and  lower  extremities,  beginning  with  the 
thoracic  aorta. 

THE    THORACIC    AORTA 

The  thoracic  aorta  commences  at  the  left  side  of  the 
lower  border  of  the  fourth  dorsal  vertebra;  it  terminates 
at  the  aortic  opening  in  the  diaphragm,  in  front  of  the  last 
dorsal  vertebra. 

Its  branches  are  as  follows : 

Pericardiac.  Esophageal. 

Bronchial.  Posterior  mediastinal. 

Intercostal. 


THE    CIRCULATORY   OR    VASCULAR   SYSTEM      III 

The  pericardiac  arteries  are  small  and  irregular,  and 
are  distributed  to  the  pericardium. 

The  bronchial  arteries  are  three  in  number — one 
for  the  right  lung  and  two  for  the  left ;  they  are  distributed 
to  the  lung-tissue,  and  also  provide  small  branches  that 
supply  the  bronchial  glands,  esophagus,  and  peri- 
cardium. 

The  esophageal  arteries  number  five  or  six;  they 
are  given  off  from  the  anterior  part  of  the  aorta,  and  are 
distributed  to  the  esophagus,  forming  a  chain  of  arterial 
supply  about  it.  They  anastomose  freely  with  the  ar- 
teries in  the  vicinity. 

The  posterior  mediastinal  arteries  are  small,  and 
are  distributed  to  the  lymphatic  glands  and  cellular  tissue 
of  the  posterior  mediastinum. 

The  intercostals  {posterior)  arise  from  the  posterior 
part  of  the  aorta,  and  number  ten  on  each  side.  The 
first  intercostal  space  is  supplied  by  the  superior  inter= 
costal  artery,  a  branch  of  the  subclavian.  They 
anastomose  freely  with  the  anterior  intercostal,  mam- 
mary, axillary,  epigastric,  phrenic,  and  lumbar  arteries. 
They  supply  the  vertebrae,  spinal  cord,  dorsal  muscles, 
and  skin. 

THE    ABDOMINAL   AORTA 

This  important  structure  has  been  briefly  described 
in  another  section  (page  97).  For  the  purpose  of 
making  the  nurse  more  familiar  with  this  artery  and 
its  branches,  a  more  complete  description  will  now  be 
given. 

The  abdominal  aorta  commences  at  the  aortic  opening 
in  the  diaphragm,  in  front  of  the  body  of  the  last  dorsal 
vertebra ;  descending  to  the  left  of  the  vertebral  column,  it 
terminates  on  the  body  of  the  fourth  lumbar  vertebra 
by    dividing    into    the    right     and    left    common    iliac 


112      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

arteries.     This  portion  of  the  aorta  gives  off  the  follow- 
ing branches: 

Phrenic. 

r  Gastric.  Inferior  mesenteric. 

Celiac  axis :      \  Hepatic.  Suprarenal. 

(.  Splenic.  Renal. 

Superior  mesenteric.  Lumbar. 

Spermatic  (ovarian  in  female).  Sacra  media. 

The  phrenic  arteries  supply  the  under  surface  of  the 
diaphragm.     Each  gives  off  a  superior  suprarenal  branch. 


Fig,  56. — The  abdominal  aorta :  Ai,  Common  iliac  ;  i,  external  iliac ;  h, 
internal  ihac;  sm,  middle  sacral ;  phr,  inferior  phrenic  ;  lb,  lumbar  ;  c,  celiac  ; 
mes,  superior  mesenteric  ;  mel,  inferior  mesenteric  ;  sr,  suprarenal ;  r,  renal  ; 
spi,  spermatic  ;  hi,  internal  hemorrhoidal  (after  Henle). 

The  celiac  axis  arises  from  the  aorta  opposite  the 
margin  of  the  diaphragm,  passes  out  for  \  inch,  and 
divides  into  three  branches — the  gastric,  hepatic,  and 
splenic. 


THE   CIRCULATORY  OR    VASCULAR   SYSTEM      II3 

The  gastric  (sometimes  called  the  coronary)  passes 
along  the  lesser  curvature  of  the  stomach,  anastomosing 
with  the  esophageal,  splenic,  and  hepatic  arteries. 

The  hepatic  artery  passes  along  the  border  of  the  lesser 
omentum  to  the  liver,  where  it  gives  off  the  following 
branches:  Pancreatic,  pyloric,  gastroduodenalis,  and 
cystic.  These  are  distributed  to  the  parts  indicated  by  the 
names,  and  anastomose  with  the  splenic,  gastric,  and 
superior  mesenteric  arteries. 

The  splenic  is  the  largest  of  the  three  branches  of  the 
celiac  axis.  It  passes  to  the  left  along  the  upper  border  of 
the  pancreas,  and  divides  into  five  or  six  branches,  which 
enter  the  spleen  at  its  hilum  and  are  distributed  to  the 
structure  of  the  spleen.  This  is  what  is  called  a  serpentiyie 
artery,  since  it  pursues  an  extremely  tortuous  course.  It 
has  the  following  branches : 

Pancreaticae  parvse.  Vasa  brevia. 

Pancreatica  magna.  Gastro-epiploica  sinistra. 

The  superior  mesenteric  artery  is  given  off  from 
the  abdominal  aorta  about  \  inch  below  the  celiac  axis, 
and  passes  downward  and  forward  from  left  to  right;  it 
is  distributed  to  the  small  intestine,  with  the  exception  of 
the  first  part  of  the  duodenum.    It  gives  off  five  branches: 

Inferior  pancreaticoduodenal.  Ileocolic. 

Vasa  intestini  tenuis.  .  Colica  dextra. 

Colica  media. 

The  inferior  mesenteric  artery  is  given  off  from 
the  aorta  about  2  inches  above  the  bifurcation,  passing  to 
the  left  and  supplying  the  descending  colon,  sigmoid 
flexure,  and  part  of  the  rectum,  anastomosing  with  the 
colica  media,  and  distributing  branches  to  the  transverse 
colon.  It  gives  off  the  following  branches:  colica  sinistra, 
sigmoid,  and  superior  hemorrhoidal;  these  furnish  nutri- 

8 


114      ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

tion  to  the  pelvic  tissues  and  rectum,  and  freely  anasto- 
mose with  arteries  therein  contained. 

The  suprarenal  arteries  are  two  small  branches  that 
are  distributed  to  the  suprarenal  capsule  of  the  kidney. 

The  renal  arteries  are  two  large  branches  given  off 
-,from  the  abdominal  aorta,  the  right  being  longer  and  lower 
than  the  left.  Before  entering  the  kidney.  _they  divide 
into  several  branches  which  are  distributed  to  the  sub- 
stance of  the  organ.  Each  vessel  gives  off  small  branches 
— one  to  the  ureter  and  the  other  to  the  suprarenal  cap- 
sule. 

The  spermatic  arteries  (ovarian  in  the  female) 
are  given  off  in  front  of  the  abdominal  aorta  on  each  side, 
below  the  renals,  and  pass  behind  the  peritoneum.  In 
the  male  they  pass  out  through  the  inguinal  canal  to  the 
testicles ;  in  the  female  they  run  between  the  layers  of  the 
broad  ligament  to  reach  the  ovary,  Fallopian  tubes,  and 
uterus.  In  their  course  they  supply  the  several  organs 
mentioned. 

The  lumbar  arteries  are  usually  five  in  number  on 
each  side;  they  pass  about  the  lumbar  vertebrae,  and 
divide  into  two  branches — one  dorsal  and  one  abdominal 
— which  are  distributed  to  the  muscles  of  the  back,  the 
vertebrae,  the  spinal  cord,  and  the  abdominal  muscles. 

The  sacra  media  arises  from  the  bifurcation  of  the 
abdominal  aorta,  passes  along  the  anterior  part  of  the 
sacrum  to  the  coccyx,  and  supplies  branches  to  the  rectum 
and  anterior  sacral  nerves ;  it  anastomoses  with  the  lateral 
sacral  arteries. 

The  Common  Iliac  Arteries. — As  has  been  said,  the 
abdominal  aorta  divides  into  the  common  iliac  arteries.*- 
These  extend  from  the  bifurcation,  which  takes  place  usu- 
ally at  the  fourth  or  the  fifth  lumbar  vertebra.     These 
arteries  are  about  2  inches  long,  and  pass  outward  and 


THE   CIRCULATORY  OR    VASCULAR   SYSTEM      II5 

downward  to  the  pelvis  opposite  to  the  sacro-iliac  sym- 
physis, where  they  divide  into  the  internal  and  the  external 
iliac.  The  right  artery  is  longer  than  the  left.  In  the 
female  the  bifurcation  is  more  expanded  than  in  the 
male. 

The  Internal  Iliac  Artery. — This  is  a  short  branch  from 
the  common  iliac,  extending  to  the  sacrosciatic  foramen, 
where  it  divides  into  two  branches — the  anterior  and  the 
posterior — which  subdivide  into  the  following:  c- 

Anterior.  Posterior. 

Superior  vesical.  Iliolumbar. 

Middle  vesical.  Lateral  sacral. 

Inferior  vesical.  Gluteal. 

Middle  hemorrhoidal. 

Uterine. 

Vaginal. 

Obturator. 

Sciatic. 

Internal  pudic. 

The  external  iliac  artery  passes  along  the  psoas  muscle 
to  Poupart's  ligament.  A  line  drawn  from  the  umbilicus 
to  the  middle  of  Poupart's  ligament  indicates  its  course. 
In  addition  to  branches  to  the  psoas  muscle  and  to  the 
neighboring  lymphatic  glands,  it  gives  off  the  deep  epi- 
gastric and  the  deep  circumflex  iliac. 

The  Femoral  Artery. — When  the  external  iliac  passes 
under  Poupart's  ligament  it  becomes  the  femoral.  From 
this  point  it  passes  down  the  thigh.  A  line  drawn  from 
the  mid-point  between  the  anterior  superior  spine  of  the 
ilium  and  the  symphysis  pubis  to  the  inner  side  of  the 
internal  condyle  of  the  femur  indicates  its  course.  To- 
gether with  its  vein  it  is  enclosed  in  a  strong  sheath,  but  is 
separated  from  the  vein  by  a  partition  of  fibrous  septum. 


Il6      ANATOMY  AND  PHYSIOLOGY  FOR   NURSES 

It  is  divided  into  a  superficial  and  a  deep  branch,  which  are 
further  subdivided  into  the  following  branches: 


Superficial 
femoral 


Superficial  circumflex  iliac. 

Superficial  epigastric. 

Superficial  external  pudic.     j^^^  [  External  circumflex. 

Deep  external  pudic.  femoral  •     )  ^"^^^°^^  circumflex. 

Muscular.  "     ^  Three  perforating. 

Anastomotica  magna. 


The  popliteal  artery  commences  at  the  opening  in 
the  adductor  magnus,  and,  passing  downward  behind  the 
knee-joint,  it  divides  at  the  lower  border  of  the  popliteus 
muscle  into  the  anterior  and  the  posterior  tibial.  The 
walls  are  exceedingly  thick,  thus  protecting  the  artery, 
which  is  subjected  to  strain  from  the  pressure  that  is 
applied  from  without,  as  in  flexing  the  limb  on  the  thigh. 
It  is  the  deepest  structure  in  the  popliteal  space.  The 
branches  which  it  gives  off  are  as  follows : 

Superior  muscular,  Superior  external  articular. 

Inferior  muscular  or  sural.  Superior  internal  articular. 

Cutaneous.  Inferior  internal  articular. 

Azygos  articular.  Inferior  external  articular. 

The  anterior  tibial  artery  passes  through  the 
interosseous  membrane  to  the  anterior  tibial  region,  and 
runs  down  the  anterior  part  of  the  leg  to  the  ankle-joint, 
where  it  becomes  the  dorsalis  pedis.  The  branches  are 
the  recurrent,  muscular,  external  malleolar,  and  internal 
malleolar. 

The  dorsalis  pedis  artery  is  on  the  tibial  side  of 
the  dorsum  of  the  foot,  passing  from  the  ankle  to  the  base 
of  the  metatarsal  bone  of  the  great  toe,  where  it  gives  off 
a  branch — the  dorsalis  hallucis;  it  then  passes  to  the  sole 
of  the  foot,  between  the  heads  of  the  interosseous  muscle, 
and  completes  the  plantar  arch  by  anastomosing  with  the 
external   plantar   artery.     Its   branches   are   the   tarsal. 


THE    CIRCULATORY  OR    VASCULAR   SYSTEM      11/ 


Fig.  57- — Femoral  artery  :  cfi. 
Common  femoral;  esp,  superficial 
epigastric  ;  cis,  superficial  circum- 
flex iliac  ;  pue,  external  pudic  ;  prf, 
deep  femoral ;  cjl,  external  circum- 
flex of  thigh  ;  cfm,  internal  circum- 
flex of  thigh ;  pp-,  first  perforat- 
ing ;  pf^,  second  perforating ;  pf^, 
third  perforating;  a^s,  anastomotica 
magna;  sf,  superficial  femoral  (after 
Henle). 


Fig.  S8. — Posterior  tibial  artery : 
Po,  Popliteal;  Tlz,  anterior  tibial; 
Tp,  posterior  tibial ;  Pe,  peroneal ; 
ria,  anterior  tibial  recurrent ;  rtp, 
posterior  tibial  recurrent ;  fs,  su- 
perior fibular ;  nuf,  nutrient  of 
fibula ;  nut,  nutrient  of  tibia ;  ppf, 
anterior  peroneal ;  com,  transverse 
anastomotic  ;  mam,  anterior  medial 
malleolar ;  mal,  internal  malleolar ; 
mpm,  posteromedian  malleolar ; 
cam,  middle  calcaneal ;  plm,  inter- 
nal plantar ;  ///,  external  plantar 
(after  Henle). 


metatarsal,  interosseous,  dorsalis  hallucis,  and  communi- 
cating. 


Il8      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 


The  posterior  tibial  artery  passes  down  the  tibial 
side  of  the  leg,  from  the  lower  border  of  the  popliteal 
muscle  to  the  concavity  of  the  os  calcis,  where  it  divides 
into  the  internal  and  the  external  plantar  arteries.  The 
branches  of  the  posterior  tibial  are  as  follows:  Pero- 
neal, nutrient,  muscular,  in- 
ternal calcanean,  internal 
plantar,  and  external  plantar. 
The  Pulmonary  Artery. 
—  The  pulmonary  artery 
arises  from  the  right  ven- 
tricle of  the  heart,  in  front 
of  the  aorta,  and  is  divided 
into  a  right  and  a  left  pul- 
monary artery,  which  pass 
to  the  lungs.  The  right  is 
larger  than  the  left.  These 
vessels  transmit  the  venous 
blood  to  the  lungs,  to  be 
supplied  with  oxygen.  They 
will  be  subsequently  more 
fully  described. 


Fig.  59. — Dorsal  arteries  of  foot : 
Ta,  7\nterior  tibial  ;  Dpd,  dorsal ; 
///,  anterior  peroneal  ;  ma7n,  an- 
teromedian malleolar;  mal,  inter- 
nal malleolar  ;  tsm,  internal  supra- 
tarsal ;  tip,  external  tarsal ;  tla, 
metatarsal  ;  pip,  deep  plantar ; 
imdx,  imd^,  imd^,  the  dorsal  in- 
terossei ;  pfp,  posterior  perforat- 
ing ;  pfa,  anterior  perforating ; 
spm,  digital  branch  of  communi- 
cating (after  Henle). 


THE    VENOUS   SYSTEM 

The  venous  system  is  that 
part  of  the  systemic  circula- 
tion which  returns  the  ven- 
ous blood  to  the  right  auricle 
of  the  heart. 

The  veins  take  their  origin  from  absorbent  radicles  from 
the  capillaries,  which  in  their  course  unite  and  reunite, 
thus  forming  larger  and  still  larger  trunks,  until  they 
finally  form  two  large  vessels — the  ascending  and  the 
descending  vena  cava.  The  circulation  in  the  veins  is 
always  in  a  direction  toward  the  heart. 


THE   CIRCULATORY  OR    VASCULAR   SYSTEM      I  I9 


There  is  no  pulsation  in  veins,  as  there  is  in  the  arteries, 
hence  the  circulation  in  them  depends  upon  a  different 
mechanism.  They  are  supplied  with  numerous  valves 
(Fig.  60),  which  prevent  any  reflux  of  blood,  and  close  in 
such  a  manner  that  the  blood  can  flow  only  toward  the 
heart. 

Physiologists  are  not  yet  in  accord  regarding  all  the  theo- 
ries that  have  been  proposed  to  account  for  the  grand 
principle  of  venous  circulation,  or  the  power  of  sustaining 
it.  The  valvular  arrangement  just  mentioned  at  once 
suggests  that  an  alternate 
contraction  and  relaxa- 
tion is  exercised  upon 
them;  such  action,  we 
can  readily  perceive,  is 
afforded  to  some  extent 
by  the  movements  of  the 
muscles,  but  this  action 
is  not  sufficiently  regular 
to  account  for  the  regu- 
larity of  the  venous  cir- 
culation. Another  action, 
however,  that  is  m.ore 
regular  and  universal,  is 
that  of  pulsation  of  the 
arteries.     The  swell  of  the 

arteries  in  the  diastolic  motion  produces  great  pressure 
in  every  part  of  the  system.  We  have  a  very  striking 
example  of  this  in  the  throbbing  pain  in  the  head  in 
some  forms  of  fever,  or  in  cases  of  inflammation,  especi- 
ally when  the  parts  are  much  swollen. 

Thus  the  impulse  of  the  heart  and  arteries  not  only 
propels  the  blood  through  the  arteries,  but  tends  indi- 
rectly also  to  force  it  forward  in  the  veins. 

There  is,   however,   another  physical  principle  which 


Fig.  60. — Diagram  of  the  valves  of 
veins  (Morrow). 


I20      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

is  cited  as  an  agency  in  venous  circulation,  and  that  is 
capillary  attraction.  Still  another  factor  responsible  for 
the  return  of  the  venous  blood  to  the  heart  is  furnished  by 
thoracic  aspiration.  The  following  illustrations  of  the 
venous  system  give  a  fair  conception  of  the  course  of  the 
veins  and  shows  their  relation  to  the  arterial  system. 

The  blood  is  of  much  darker  color  in  the  veins  than  in 
the  arteries.  This  change  takes  place  during  the  passage 
of  the  blood  through  the  capillary  system,  and  is  depend- 
ent upon  the  phenomena  of  combustion  and  the  general 
metamorphosis  of  the  materials  of  the  tissues,  all  of  which 
are  in  contact  with  the  capillary  system. 

The  veins  of  the  body  are  divided  into  two  groups :  those 
that  pass  by  way  of  the  superior  and  those  that  empty  into 
the  inferior  vena  cava.  The  blood  from  the  lower  ex- 
tremities is  brought  by  way  of  the  inferior  vena  cava;  the 
blood  from  the  brain,  neck,  and  face  passes  through  the 
internal  and  the  external  jugular  veins,  which  unite  with 
the  venous  trunk  from  the  upper  extremity  to  form  the 
superior  vena  cava. 

The  external  jugular  vein  starts  at  the  angle  of  the 
lower  jaw  and  terminates  in  the  subclavian  vein. 

The  internal  jugular  vein  passes  downward  in 
line  with  the  common  carotid,  and  unites  with  the  sub- 
clavian to  form  the  innominate  vein. 

The  subclavian  vein  receives  the  blood  from  the 
arm.  The  veins,  with  the  exception  of  the  superficial 
branches,  accompany  the  arteries  in  the  same  sheath. 
The  right  and  left  azygos  veins  receive  the  blood 
from  the  spine. 

The  innominate  veins  unite  in  forming  the  superior 
vena  cava.  The  inferior  vena  cava  is  formed  by  the 
union  of  the  two  common  iliacs,  which  receive  all  the  blood 
from  the  deep  and  the  superficial  veins  of  the  lower  limbs. 
The  large  vein  of  the  leg  is  called  the  internal  saphenous. 


THE   CIRCULATORY  OR    VASCULAR   SYSTEM      121 

Sinuses  are  venous  channels  found  chiefly  within  the 
cranium.  They,  together  with  the  blood-supply  of  the 
cerebrum,  will  be  considered  in  the  chapter  on  the  Nervous 
System. 

VEINS  OF  THE  HEAD  AND  NECK 

The  veins  of  the  exterior  of  the  head  are  as  follows: 

Facial.  Temporomaxillary. 

Internal  maxillary.  Posterior  auricular. 

Temporal.  Occipital. 

(The  student  will  bear  in  mind  that  the  veins  bear  the 
same  names  as  the  arteries,  and  are  generally  in  the  same 
sheath;  this  is  particularly  true  of  the  deep  trunks.) 

The  facial  vein  takes  its  commencement  on  the 
anterior  part  of  the  head,  from  a  plexus  of  the  temporal 
branches.  Under  the  name  frontal  vein  it  passes  along 
the  middle  line  of  the  forehead  to  the  root  of  the  nose, 
where  it  is  connected  with  its  fellow  of  the  opposite  side 
by  a  communicating  branch.  It  is  divided  into  several 
branches,  which  are  distributed  about  the  anterior  part 
of  the  face;  it  receives,  in  its  course,  the  supra-orbital,  the 
frontal  vein,  and  the  dorsal  veins  of  the  nose;  also  all 
veins  that  correspond  with  the  branches  of  the  facial 
artery. 

The  internal  maxillary  vein  joins  the  temporal 
vein. 

The  temporal  vein  drains  the  region  of  the  temple  and 
enters  the  parotid  gland,  after  which  it  unites  with  the 
internal  maxillary  vein  to  form  the  temporomaxillary. 

The  temporomaxillary  vein  is  formed  by  the  union 
of  the  temporal  and  internal  maxillary.  It  divides  into 
two  branches,  one  joining  the  facial  vein,  and  the  other 
joining  with  the  posterior  auricular  to  form  the  external 
jugular. 


122      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

The  posterior  auricular  vein  begins  at  the  vertex, 
runs  behind  the  ear,  and  helps  to  form  the  external  jugular 
vein. 


Fig.  6i. — The  internal  jugular  and  common  facial  veins  and  their 
branches.  The  zygoma  and  the  left  side  of  the  inferior  maxilla,  together 
with  the  masseter,  have  been  removed:  i,  Pterygoid  muscle;  2.  styloglossus 
muscle  ;  3,  sublingual  gland;  4,  hyoglossus  muscle  ;  5,  geniohyoid  muscle  ; 
6,  mylohyoid  muscle;  7,  sternohyoid  muscle;  8,  thyrohyoid  muscle;  9, 
omohyoid  muscle;  10,  stylohyoid  muscle;  11,  styloglossus  muscle;  12, 
stylopharyngeus  muscle ;  ji,  j'e,  internal  and  external  jugular  vein ;  ph, 
pharyngeal  vein ;  dl,  dorsal  vein  of  tongue ;  /,  lingual  veins ;  s,  sublingual 
vein  ;  tsti,  superior  thyroid  vein  ;  fc,  common  facial  vein  ;  fa,  anterior  facial 
vein; /«^  superficial,  and /a",  deep  branches  of  same;/,  frontal  vein;  a, 
angular  vein  ;  os,  superior  ophthalmic  vein  ;  n,  nasal  vein  ;  lbs,  superior  labial 
vein  ;  _/5),  posterior  facial  vein  ;  y^',y5^",  superficial  and  deep  branches  of 
same;  tps,  tpm,  /"/r,  superficial,  middle,  and  deep  temporal  veins;  /^.ptery- 
goid plexus  ;  oi,  inferior  ophthalmic  vein  ;  sea,  anterior  jugular  vein  (after 
Henle). 


The  occipital  vein  follows  the  direction  of  the 
occipital  artery,  terminating  usually  in  the  internal 
jugular. 

The  veins  of  the  neck,  which  return  the  blood  from 


THE   CIRCULATORY  OR    VASCULAR   SYSTEM     1 23 

the   head   and   face,   are   the   internal   jugular,    anterior 
jugular,  external  jugular,  and  vertebral. 

The  internal  jugular  vein  is  formed  by  the  lateral 
and  inferior  petrosal  sinuses  outside  of  the  jugular  for- 
amen; it  unites  with  the  subclavian  to  form  the  innomi- 
nate vein.  The  facial,  lingual,  pharyngeal,  superior,  and 
middle  thyroid  veins  unite  to  make  up  the  supply  on  its 
course.  At  the  base  of  the  neck,  where  it  unites  with  the 
subclavian  vein,  is  a  pair  of  valves. 


/lbs 


Fig.  62. — Innominate  vein  and  its  branches:  i,  Mylohyoid  muscle;  2, 
root  of  tongue;  3,  larynx;  4,  thyroid  gland;  5,  trachea;  cs,  superior  vena 
cava;  Abd,  Abs,  right  and  left  innominate  veins;  6",  subclavian  vein  ;  ji,je, 
internal  and  external  jugular  veins;  tsu,  ti,  superior  and  inferior  thyroid 
vein  ;  cvp,  deep  cervical  vein  ;  v,  vertebral  vein  ;  m7?ti,  internal  mammary  ; 
is,  superior  intercostal  vein  ;  sea,  anterior  jugular  vein  ;  "-••,  thyroid  plexus 
(after  Henle). 


The  anterior  jugular  begins  by  many  small  veins 
about  the  hyoid  bone  in  the  median  line,  and  enters  the 
subclavian  vein. 

The  external  jugular  vein,  formed  by  a  division  of 
the  temporomaxillary  and  the  posterior  auricular,  passes 
over  the  sternomastoid  muscle,  thence  downward,  and 
terminates  in  the  subclavian  vein. 

The  vertebral  vein  follows  the  course  of  the  artery, 


124      ANATOMY  AND  PHYSIOLOGY  FOR   NURSES 

but  drains  only  the  scalp  in  the  occipital  region,  since  it 
does  not  come  from  the  cranial  cavity.  It  enters  the 
subclavian  vein. 

The  inferior  thyroid  veins  receive  the  blood  from 
the  thyroid  gland.  Bach  unites  with  its  fellow,  and,  along 
with  the  middle  and  superior,  they  form  a  plexus  in  front 
of  the  trachea.  The  right  terminates  in  the  right  in- 
nominate vein,  and  the  left  in  the  left  innominate  vein. 

VEINS   OF   THE   UPPER   EXTREMITIES 

The  veins  of  the  upper  extremities  are  superficial  and 
deep;  the  latter  accompany  the  arteries,  and  are  called 
mncB  comites;  they  are  sometimes  enclosed  in  the  same 
sheath.  The  brachial  vencB  comites  are  situated  on  each 
side  of  the  artery,  and  unite  with  the  basilic  vein  to  form 
the  axillary  vein.  The  axillary  becomes  the  subclavian, 
and  the  subclavian  unites  with  the  internal  jugular  to  form 
the  vena  innominata. 

The  superficial  veins  of  the  arm  are : 

Anterior  ulnar.  Cephalic. 

Posterior  ulnar.  Median. 

Basilic.  Median  basilic. 

Radial.  Median  cephalic. 

The  anterior  ulnar"  vein  collects  the  blood  from  the 
inner  part  of  the  hand,  ascends  to  the  elbow,  and  unites 
with  the  median  basilic  to  form  the  basilic  vein. 

The  posterior  ulnar  vein  takes  its  beginning  at  the 
back  of  the  hand,  unites  with  the  veins  of  the  fingers, 
ascends  to  the  back  part  of  the  elbow,  and  terminates  in 
the  anterior  ulnar  vein. 

The  basilic  vein  arises  from  the  ulnar,  and  is  formed 
by  the  coalescence  of  the  median  basilic  with  the  ulnar 
veins;  it  is  situated  on  the  inner  side  of  the  arm,  passing 
upward  to  the  axilla,  terminating  in  the  axillary. 


THE    CIRCULATORY  OR    VASCULAR   SYSTEM      1 25 


The  radial  vein  starts  at  the  back  of  the  wrist, 
receiving  tributaries  from  the  deep  veins  of  the  palm, 
and  connects  with  the  several  venous  branches  from  the 
fingers  and  thumb,  where  it 
is  increased  in  size;  it  passes 
on  upward,  and  at  the  bend 
of  the  elbow  it  runs  forward 
and  unites  with  the  median 
cephalic  to  form  the  cephalic 
vein. 

The  cephalic  vein  passes 
upward  on  the  outer  side  of 
the  arm  and  terminates  in 
the  axillary  vein. 

The  median  vein  takes  its 
start  at  the  wrist  and  palm 
of  the  hand;  at  the  elbow  it 
receives  other  branches  from 
the  deep  structures,  and 
divides  into  two  branches — 
the  median  basilic  and  me- 
dian cephalic. 

The  median  cephalic 
unites  with  the  radial  to 
form  the  cephalic  vein. 

The  median  basilic  unites 
with  the  ulnar  to  form  the 
basilic  vein. 

The  deep  veins  of  the  upper 
extremity  follow  the  course 
of  the  arteries.  They  have  numerous  anastomoses, 
not  only  with  one  another,  but  with  the  superficial 
veins. 

The  axillary/ vein  is  formed  by    the    union    of    the 
brachial  ve^^iae  comites  with  the  basilic;  it  also  receives 


Fig.  63. — Superficial  veins  of 
upper  limb:  i,  Cephalic  vein; 
2,  basilic  vein  ;  3,  radial  vein  ;  4, 
median  cephalic  vein  ;  5,  median 
vein;  6,  median  basilic  vein;  7, 
anterior  ulnar  vein;  8,  posterior 
ulnar  vein  (after  Quain). 


126      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 


several  other  branches  from  the  axillary  region,  and  ter- 
minates in  the  subclavian. 

The  subclavian  vein  crosses  the  first  rib  and  passes 
below  the  clavicle;   it  unites  with   the  internal  jugular 

vein  to  form  the  innominate 

vein. 


VEINS    OF   THE    LOWER   EX- 
TREMITIES 

The  deep  veins  of  the  leg 
accompany  the  arteries  in 
pairs,  and  form  the  venae 
comites  of  the  anterior  and 
posterior  tibial  arteries.  The 
tibial  veins  unite  and  form 
the  popliteal  vein. 

The  popliteal  vein  passes 
through  the  popliteal  space 
and  to  the  outer  side  through 
an  opening  in  the  adductor 
magnus  muscle,  and  becomes 
the  femoral  vein.  It  usually 
contains  four  valves,  and  it 
also  receives  blood  from  the 
short  saphenous  vein. 

The  femoral  vein  com- 
mences at-^the  ojllning  in  the 
adductor  magnus  muscle,  and 
is  enclosed  in  the  femoral 
sheath;  it  enters  the  pelvis 
beneath  Poupart's  ligament,  and  then  becomes  the  ex- 
ternal iliac  vein.  The  valves  are  about  five  in  number. 
It  receives  several  veins  from  the  muscular  structure,  as 
well  as  the  deep  femoral  and  the  long  saphenous  veins. 
The  deep  femoral  is  made  up  of  small  branches  that 


Fig.  64. — Superficial  veins  of 
lower  limb  :  C,  Femoral  ,yein  ; 
Sam,  Sap,  long  and  short  s'aph- 
enous  veins  ;  Rd,  dorsal  rete  of 
foot;  //,  plantar  vein  (after 
Henle). 


THE   CIRCULATORY  OR    VASCULAR  SYSTEM     '12/ 

are  associated  with  the  artery  of  the  same  vein,  and 
terminates  in  the  femoral  vein,  below  Poupart's  ligament. 

The  short  saphenous  vein  begins  in  the  arch  on 
the  dorsum  of  the  foot;  it  ascends  the  outer  and  back 
part  of  the  leg,  receives  many  branches  from  the  posterior 
part  of  the  leg,  and  perforates  the  deep  fascia  to  terminate 
in  the  popliteal  vein. 

The  long  saphenous  vein  begins  at  the  inner  end  of 
the  arch  on  the  dorsum  of  the  foot,  and  passes  to  the  inner 
part  of  the  ankle;  it  then  ascends  to  the  knee,  passes  be- 
hind the  condyle  of  the  femur  upward  to  the  saphenous 
opening,  where  it  enters  the  femoral  sheath  and  terminates 
in  the  femoral  vein  below  Poupart's  ligament.  It  receives 
the  cutaneous  veins  of  the  thigh,  and  unites  with  many 
deep  branches.  At  the  saphenous  opening  it  unites  with 
the  superficial  epigastric  and  superficial  circumflex  iliac 
veins,  as  well  as  with  the  superficial  external  pudic. 
This  vein  is  of  importance,  for  in  phlebitis  of  the  lower 
extremity  it  is  generally  implicated;  in  the  varicosity 
which  occurs  in  the  leg  it  is  also  this  venous  trunk  that  is 
usually  involved. 

VEINS   OF  THE   TRUNK 

The  innominate  veins  are  two  large  trunks,  formed 
one  on  each  side,  by  the  union  of  the  internal  jugular  and 
subclavian.  The  ri^t  innominate  unites  with  that  o*f  the 
opposite  side  and  forms  the  superior  vena  cava ;  it  receives 
the  right  internal  mammary  and  the  right  inferior  thyroid 
veins.  The  lejt  innominate  passes  obliquely  across  the 
chest,  and  unites  with  the  right  innominate  to  form  the 
superior  vena  cava. 

The  superior  vena  cava  is  a  short  branch,  about 
3  inches  in  length,  formed  by  the  union  of  the  two  in- 
nominate veins;  it  enters  the  pericardium  and  terminates 
in  the  right  auricle  of  the  heart. 


128      ANATOMY  AND  PHYSIOLOGY  FOR   NURSES 

The  external  iliac  accompanies  the  artery  of  the  same 
name,  and  unites  with  the  internal  iliac  to  form  the  com- 
mon iliac  vein. 

The  internal  iliac  drains  that  area  of  the  pelvis  which 
is  supplied  by  the  artery  of  the  same  name,  and  unites 
with  the  external  iliac  to  form  the  common  iliac  vein. 

The  uterine  plexuses  are  situated  about  the  vagina  and 
uterus,  between  the  two  layers  of  the  broad  ligaments. 
The  vesical  and  prostatic  plexuses  receive  blood  from 
the  genital  organs  and  the  bladder. 

Bach  common  iliac  vein  is  formed  by  the  union  of  the 
external  and  internal  iliac  veins  of  the  corresponding  side ; 
at  the  origin  of  the  right  common  iliac  artery  the  two 
common  iliac  veins  unite  and  form  the  inferior  vena 
cava. 

The  inferior  vena  cava,  as  has  been  said,  is  formed  by 
the  union  of  the  two  common  iliac  veins ;  it  ascends  along 
the  vertebral  column  to  the  right  of  the  abdominal  aorta, 
passing  through  the  diaphragm,  and  terminating  in  the 
inferior  and  posterior  part  of  the  right  auricle  of  the  heart ; 
this  vein  contains  no  valves.  It  receives,  in  its  course,  the 
following  veins:  Lumbar,  right  spermatic,  renal,  supra- 
renal, phrenic,  and  hepatic. 

The  AzygOS  Veins. — These  connect  the  superior 
and  the  inferior  vena  cava,  taking  the  place  of  these 
vessels  in  that  part  of  the  chest  occupied  by  the  heart. 

The  superior  intercostal  veins  receive  the  veins 
of  the  first  and  second  intercostal  spaces;  the  right  ter- 
minates in  the  vena  azygos  major,  the  left  in  the  left  in- 
nominate. The  vena  azygos  major  drains  the  remaining 
intercostal  spaces  on  the  right  side  and  empties  into  the 
superior  vena  cava.  The  remaining  intercostal  spaces  on 
the  left  are  drained  by  the  left  upper  and  lower  azygos 
veins;  both  of  these  vessels  frequently  terminate  in  the 
vena  azygos  major. 


THE   CIRCULATORY  OR    VASCULAR  SYSTEM     1 29 

The  Vertebral  and  Spinal  Veins. — The  plexuses 
of  veins  of  the  vertebral  column  and  spinal  cord  are: 
The  dorsispinal,  meningorachidian,  and  medullispinal. 


Fig.  65. — Veins  and  arteries  of  the  thoracic  and  abdominal  cavities :  i, 
Root  of  right  lung  ;  2,  section  of  diaphragm  ;  3,  suprarenal  body  ;  4,  kidney  ; 
5,  psoas  magnus  muscle  ;  6,  quadratus  lumborum  muscle  ;  Aa,  descending 
aorta;  aA,  arch  of  aorta ;  Ab,  innominate  artery;  cs,  left  carotid  artery; 
Ss,  left  subclavian  artery  ;  c,  celiac  artery  ;  mes,  mei,  superior  and  inferior 
mesenteric  arteries  ;  cs,  ci,  superior  and  inferior  venae  cavse  ;  Abd,  Abs,  right 
and  left  innominate  veins;  S,  subclavian  vein  ;  Je,Ji,  external  and  internal 
jugular;  az,  vena  azygos  major  ;  ic,  intercostal  vein  ;  h,  hepatic  veins;  phr, 
phrenic  vein  and  artery ;  .sr,  suprarenal  vein  ;  r,  renal  artery  and  vein ;  lb, 
lumbar  vein  ;  spl,  internal  spermatic  artery  and  vein  ;  sm,  middle  sacral 
artery  and  vein  ;  ai,  common  iliac  artery  and  vein  ;  H,  hypogastric  artery 
and  vein  ;  /,  iliac  artery  and  vein  (after  Henle). 


The    Cardiac   Veins. — These  veins  return  the  blood 
from  the  muscular  structure  of  the  heart.     They  are 
9 


130      ANATOMY  AND  PHYSIOLOGY  FOR   NURSES 

divided  as  follows:  Great  cardiac  vein,  posterior  cardiac 
vein,  anterior  cardiac  vein,  and  venae  Thebesii.  They 
collect  the  blood  from  the  several  portions  of  the  heart, 
and  terminate  in  the  right  auricle. 

THE   PORTAL   CIRCULATION 

The  portal  circulation  is  a  part  of  the  general  sys- 
temic circulation.  The  stomach,  intestines,  pancreas, 
and  spleen  receive  their  arteries  from  the  aorta,  and  the 
blood,  on  leaving  these,  is  received  into  various  veins, 
which  unite  to  form  the  portal  vein;  this  enters  the  sub- 
stance of  the  liver  and  breaks  up  into  numerous  capillaries. 
The  portal  vein  not  only  returns  venous  blood  from  the 
gastro-intestinal  tract,  but  also  carries  nutritive  products 
to  the  liver,  which  are  there  still  further  elaborated. 
The  blood  is  then  collected  by  the  hepatic  vein,  which 
opens  into  the  inferior  vena  cava  just  before  the  vessel 
enters  the  right  auricle. 

The  portal  system  of  veins  is  formed  by  the  union 
of  the  superior  and  inferior  mesenteric,  splenic,  and  gas- 
tric veins,  and  collects  the  blood  from  the  digestive  viscera. 
The  resulting  trunk  divides  in  its  course  to  the  transverse 
fissure  of  the  liver  into  a  branch  each  for  the  right  and 
left  lobe,  which  ramify  to  form  plexuses  in  the  liver. 
The  blood  from  the  hepatic  artery  furnishes  blood  to  this 
vein  in  the  interior  of  the  liver,  and  exterior  to  this  organ 
the  vein  unites  with  the  pyloric  and  coronary  veins. 
The  blood  so  collected  passes  through  the  liver  and,  as 
previously  stated,  is  transmitted  to  the  inferior  vena 
cava  by  the  hepatic  vein. 

THE   PULMONARY   QRCULATION 

The  pulmonary  artery,  carrying  venous  blood, 
leaves  the  right  ventricle  and  divides  into  branches, 
one  for  each  lung.     Inside  the  lung  this  vessel  breaks 


THE   CIRCULATORY  OR    VASCULAR   SYSTEM      I3I 

Up  into  small  branches,  which  form  a  network  around 
the  alveoli,  or  air-cells.  The  oxygenated  blood  is  col- 
lected by  the  pulmonary  veins  and  carried  to  the  left 
auricle. 

The  two  auricles  contract  and  force  the  blood  into  the 
ventricles;  the  two  ventricles  then  contract,  and  the 
tricuspid  and  mitral  valves  close  their  orifices,  the  blood 
being  propelled  on  into  the  large  vessels  (the  pulmonary 
artery  and  the  aorta),  the  semilunar  valves  then  closing. 
The  blood  cannot  get  from  the  right  side  of  the  heart  to 
the  left  without  passing  through  the  lungs,  or  lesser  cir- 
culation; neither  can  the  blood  get  from  the  left  side  of  the 
heart  to  the  right  without  passing  around  the  general  or 
systemic  circulation. 

The  Pulmonary  Veins. — The  pulmonary  veins  are 
formed  by  the  union  of  the  capillaries  in  the  lung;  they 
unite  in  two  trunks  from  each  lung,  discharging  their 
blood  into  the  left  auricle  of  the  heart.  As  has  been 
stated  before,  this  is  an  instance  where  the  veins  transmit 
arterial  blood.  In  some  instances  there  are  three  veins  on 
the  right  side,  which  terminate  in  a  common  opening  in 
the  auricle.     There  are  no  valves  in  the  pulmonary  veins. 

THE  BLOOD 

We  have  previously  described  the  manner  in  which 
the  blood  passes  through  the  heart  in  circulating  through 
the  body.  It  now  remains  for  us  to  consider  the  function 
of  the  blood,  and  to  give  a  description  of  the  manner  in 
which  it  is  oxygenated  and  replenished  with  nutritive 
matter. 

The  blood  is  a  homogeneous  liquid,  possessing  a  slight 
degree  of  viscidity,  with  a  consistency  and  density  some- 
what greater  than  water.  It  is  especially  distinguished 
by  its  color,  which  is  usually  of  a  bright  scarlet  when  it  is 
drawn  from  an  artery,  and  of  a  dark  red  or  purple,  some- 


132      ANA  TOM V  AND  PH YSIOL  OGY  FOR  NURSES 

times  almost  approaching  to  black,  when  it  is  drawn  from 
a  vein.  It  has  a  salty  taste  and  a  peculiar  odor.  The 
reaction  is  faintly  alkaline;  at  a  temperature  of  60°  F.  the 
specific  gravity  is  1.055.  ^^e  temperature  of  the  blood 
as  it  passes  through  its  course  in  the  arteries  is  about 
100°  F.,  but  it  may  vary  under  different  circumstances  in 
health  from  fatigue,  over  action,  and  other  conditions. 
It  coagulates  rapidly,  the  serum  separating  and  leaving  the 
clot,  which  is  termed  the  crassamentum. 

Distribution. — After  leaving  the  arteries  the  blood 
passes  through  the  capillary  networks  of  the  various  tissues, 
where  the  nutriment  diffuses  through  the  delicate  vessel 
walls  and  nourishes  the  part.  At  the  same  time  the  waste 
materials  resulting  from  tissue  changes  are  thrown  into 
the  circulation  to  be  carried  away  and  eliminated  from  the 
body. 

The  blood  is  composed  of  the  plasma  or  liquor  sanguinis, 
and  of  the  corpuscles.  The  plasma  contain  proteids,  fats, 
extractive  matters,  and  salts. 

The  Corpuscles. — The  corpuscles  of  the  blood  are 
of  two  kinds,  and  are  known  as  the  red  and  the  white 
corpuscles.  The  red  corpuscles  exist  in  greater  number 
than  the  white.  The  blood,  therefore,  is  a  fluid,  which 
provides  a  means  of  suspending  these  important  constitu- 
ents; this  fluid  is  named  liquor  sanguinis  or  "plasma,"  and 
must  not  be  confused  with  the  "serum"  (see  p.  136),  which 
is  formed  during  the  coagulation  of  blood.  It  is  serum  and 
something  more,  for  it  contains  one  at  least  of  the  elements 
or  factors  from  which  fibrin  is  formed. 

Tiie  table  from  "Gray's  Anatomy"  will  show  the  rela- 
tion, which  will  be  easily  understood  by  the  nurse: 


Blood 


Corpuscle  {g°!-d33         |^,„^_ 
Liquor  sanguinis  |  |^J^JJJ  J 


THE   CIRCULATORY  OR    VASCULAR  SYSTEM      1 33 

The  relative  proportion  of  the  white  to  the  red  cor- 
puscles has  been  variously  estimated  by  many  observers, 
and  varies  from  i  to  400  to  i  to  1200. 

The  red  corpuscles  {erythrocytes)  are  round  biconcave 
discs;  their  average  diameter  is  estimated  to  be  about 
■^-Q-Q  of  an  inch.  They  vary  in  size  when  disease,  such  as 
anemia,  exists. 

Composition. — The  composition  of  the  red  cell  is  esti- 
mated to  be  as  follows : 

Water 90.0  per  cent. 

Hemoglobin 36.0       *' 

Proteids 3.2       " 

Lecithin  and  cholesterin 0.2       " 

Inorganic  salts 0.6       *' 

Their  color  is  due  to  the  hemoglobin  which  they  contain ; 
by  some  the  color  is  said  to  be  due  to  iron.  The  function 
of  the  red  corpuscles  is  to  carry  oxygen  (through  the  in- 
tervention of  the  hemoglobin  they  contain);  therefore, 
they   are    denominated    "oxygen   carriers."     The   blood 


I' 


»6* 


Fig.  66. — Cells  of  blood :  a,  Colored  blood-corpuscles  seen  on  the  flat 
6,  on  edge;  c,  in  rouleau;  d,  blood-platelets  (Leroy). 


passing  to  the  lungs  receives  a  new  supply  of  oxygen,  and 
returns  to  the  tissues,  where  combustion  takes  place, 
which  deposits  the  oxygen,  whereby  heat  and  energy  are 
produced;  it  now  takes  on  new  substances  (carbon  dioxid) 


134      ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

and  returns  to  the  lungs  (changed  in  character  from  red  to 
blue  blood)  through  the  venous  system. 

The  red  corpuscles  have  a  remarkable  power  of  absorb- 
ing certain  gases;  for  it  has  been  found  by  Scherer  that  a 
solution  of  hematin  imbibes  a  considerable  amount  of 
oxygen,  which  is  the  principal  constituent  of  the  composed 
strength  of  the  corpuscle  itself. 

When  examined  beneath  the  microscope,  the  red  cor- 
puscles may  be  seen  floating  in  the  liquor  sanguinis  of 
the  blood,  exhibiting  a  marked  tendency  to  approximate 
one  another;  usually  coming  into  contact  by  their  flattened 
surfaces,  so  that  a  number  of  them  aggregated  present 
the  appearance  of  a  pile  of  coins  set  upon  their  edges 
{rouleaux) .  If  the  stratum  should  be  too  thin  to  permit 
them  to  lie  in  this  manner  they  will  overlap  one  another, 
especially  so  when  the  current  is  impeded.  They  will 
be  seen  at  times  to  change  their  shape,  become  elongated, 
yet  afterward  resuming  their  natural  shape ;  the  elongation 
is  due  to  pressure  from  without,  or  from  the  diminution  of 
the  interior  of  the  vessel  in  which  they  are  contained. 

The  white  corpuscles  are  called  leukocytes;  they  are 
few  in  number  in  comparison  with  the  red;  they  are 
spheroid  in  form,  and  measure  about  a^gVo  of  an  inch  in 
diameter.  The  average  proportion  of  the  white  to  the 
red  is  i  to  500;  in  certain  diseased  conditions  the  white 
cells  are  rapidly  increased;  this  abnormal  state  is  called 
leukocytosis. 

The  white  corpuscle  has  no  limiting  membrane  like  the 
red  corpuscle ;  it  consists  of  a  mass  of  transparent  albumin- 
ous substance  called  protoplasm,  containing  one  or  more 
nuclei.  They  are  endowed  with  the  power  of  spontaneous 
movement,  and  are  thus  capable  of  changing  their  form 
and  place.  The  nuclei  vary  in  shape:  they  may  be 
crescentic,  horseshoe  shaped,  or  multiple. 

In  their  movements  they  pass  through  the  vessels  into 


THE   CIRCULATORY  OR    VASCULAR   SYSTEM      1 35 

the  lymph-spaces.  In  inflammations  the  cells  pass  out  in 
great  numbers,  and  in  suppurative  conditions  they  become 
pus  cells. 

The  white  cells  migrate  to  the  part  infected,  surround 
the  substances,  and,  through  their  protective  powers, 
prevent  further  intoxication  of  the  system.  This  sur- 
rounding and  absorption  of  infective  matter  is  termed 
phagocytosis,  and  the  white  corpuscles,  when  acting  in 
this  manner,  are  spoken  of  as  phagocytes. 

This  phagocytic  action  is  aided  by  a  certain  chemic 
substance,  called  opsonin,  which  exists  in  the  blood-plasma, 


Fig.  (ij. — Various   forms  of  leukocytes :    a.  Small  lymphocyte ;    b,   large 
lymphocyte;  c,  polymorphonuclear  neutrophile ;  d,  eosinophile  (Leroy). 

and  whose  function  is  to  act  on  disease  germs,  so  as  to 
prepare  them  for  absorption  by  the  white  cells. 

The  blood-plates  are  small  colorless  or  yellowish  bodies 
of  varying  shape,  but  considerably  smaller  than  the  red 
corpuscles.  It  is  still  uncertain  whether  these  bodies 
are  independent  structures  or  only  fragments  of  destroyed 
red  corpuscles. 

The  plasma  of  the  blood  is  a  white,  yellowish,  clear 
fluid,  largely  composed  of  water,  holding  in  solution  vari- 
ous salts,  proteid  substances,  fats,  etc.  The  proteid 
materials  are  made  up  of  albumin,  paraglobulin,  and 
fibrinogen;  the  first  two  occur  in  about  equal  quantities, 
while  the  last  is  found  in  small  quantities. 

Nutrition  is  gained  through  the  albuminoids,  which 
replenish  the  tissues  of  waste  materials  taken  up  through 
the  processes  of  combustion  and  disease. 


136      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

The  paraglobulin  has  about  the  same  effect  as  albumin. 
The  fibrinogen  produces  coagulation;  its  power  to  coagu- 
late is  such  that  it  is  impossible  to  obtain  it  in  a  fluid 
condition. 

The  mineral  salts  maintain  the  alkalinity  of  the  blood. 
The  salt  which  occurs  in  largest  quantity  is  sodium  chlorid. 

Gases. — Besides  the  constituents  just  mentioned,  the 
blood  contains  oxygen  and  carbon  dioxid;  100  volumes  of 
the  blood  contains  about  50  volumes  of  these  gases  col- 
lectively. The  proportion  varies  considerably,  but  arterial 
blood  always  contains  about  twice  as  much  oxygen  and  a 
third  less  of  carbon  dioxid  than  venous  blood.  The  sev- 
eral constituents  of  the  serum  vary  with  age,  sex,  and  tem- 
perament. The  quantity  of  water  is  greater  in  females 
than  in  males;  in  children  and  aged  persons  than  in  per- 
sons of  middle  life,  and  in  the  lymphatic  temperament 
than  in  the  sanguine.  In  healthy  males  it  has  a  range 
of  from  760  to  800  parts  in  1000,  and  an  average  of 
779;  in  healthy  females  a  range  of  773  to  813,  with  an 
average  of  791. 

The  quantity  of  blood  contained  in  the  human  body 
is  said  to  be  about  -^  of  the  body  weight. 

Clotting  of  the  Blood. — When  the  blood  is  drawn 
from  a  person  in  health,  it  solidifies  in  a  very  short  time 
into  a  jelly-like  mass,  but  retains  its  color  and  volume. 
After  it  has  remained  a  longer  time  there  will  be  noticed 
a  separation  of  the  constituents,  with  the  formation  of  a 
central  substance  which,  after  a  time,  begins  to  become 
smaller.  After  ten  to  twenty  hours  what  was  formerly 
a  coagulated  mass  of  blood  becomes  separated  into  two 
parts,  a  clot  (crassamentum)  and  a  considerable  quantity 
of  yellowish  fluid,  which  is  known  as  serum,  in  which  the 
clot  is  suspended.  The  clot  thus  formed  consists  oi  fibrin, 
which  is  associated  with  a  large  number  of  cells  or  blood- 
corpuscles.     Blood,  while  in  the  process  of  solidification, 


THE   CIRCULATORY  OR    VASCULAR   SYSTEM      1 37 

undergoes  a  chemic  action  with  the  air  through  the 
medium  of  the  blood  ferment,  fibrinogen,  which  glu- 
tinates  the  corpuscles  with  the  other  constituents  to  form 
the  clot.  This  ferment  does  not  exist  as  such  in  the  blood 
when  contained  in  the  blood-vessels,  but  is  supposed  to  be 
the  result  of  the  destruction  of  the  white  corpuscles  and 
the  blood  platelets.  Some  authors  assume  that  these 
platelets  contain  a  nuclein  body,  coupled  with  proteids, 
which  is  the  essential  factor  in  the  coagulation  of  the 
blood.  It  is  thought  that  these  structures  disintegrate 
very  rapidly  when  blood  is  drawn  from  the  body,  liberat- 
ing the  ferment,  and  so  producing  coagulation. 

Changes  in  Blood  in  Disease. — The  blood  undergoes 
various  changes  in  disease.  Traces  of  organic  com- 
pounds, viz.,  uric  acid,  urea,  keratin,  keratinin,  taurin, 
cholesterin,  and  leucin,  may  also  occur  in  the  blood,  and 
cause  serious,  if  not  fatal,  derangement. 

There  may  occur  variations  in  the  relative  proportion 
of  its  constituents;  for  instance,  in  plethora  the  red  cor- 
puscles are  said  to  be  increased  in  number,  while  in  anemia 
they  are  deficient  in  number  or  quantity.  After  the 
loss  of  great  numbers  of  the  red  blood-corpuscles  they  are 
slowly  reproduced,  hence  the  long-continued  pallor  after 
hemorrhages.  The  fibrin  is  increased  in  acute  inflam- 
mation, especially  in  those  of  the  serous  membranes,  in 
acute  rheumatism,  pneumonia,  erysipelas,  phthisis,  ton- 
sillitis, and  inflammation  of  the  lymphatic  vessels.  It 
is  always  in  excess  in  the  pregnant  female.  On  the  other 
hand,  it  is  always  diminished  in  enteric  fever,  cerebral 
hemorrhage  and  congestion,  in  scurvy,  and  after  profuse 
hemorrhages.  The  albumen  increases  in  Bright' s  disease 
and  glandular  inflammation,  erysipelas,  scarlet  fever,  and 
tuberculosis.  The  salts  of  the  serum  are  diminished  in 
enteric  fever  and  cholera.  Mixture  with  foreign  substances 
from  the  inhalation  of  noxious  gases  may  occur,  or  the 


138      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

respiration  may  become  obstructed  and  the  blood  become 
overcharged  with  the  poison.  When  the  Hver  is  inflamed 
or  its  ducts  obstructed,  the  constituents  of  the  bile  are  re- 
tained in  the  blood  or  pass  into  it  by  transudation.  In 
acute  nephritis  urea  is,  in  like  manner,  retained  within  the 
system  and  induces  the  gravest  symptoms. 

Of  the  morbid  products  which  find  their  way  into  the 
blood,  one  of  the  most  harmful  is  the  germ  of  suppuration, 
which,  under  certain  circumstances,  is  absorbed  from  the 
veins  or  from  suppurating  surfaces.  Extraneous  matters 
such  as  toxins,  germs,  or  both,  may  be  introduced  by  the 
stomach,  skin,  and  lungs,  or  more  directly  by  penetrat- 
ing wounds. 

The  quantity  of  blood  is  increased  by  food  and  in 
plethora.  It  is  diminished  in  hemorrhage  and  absti- 
nence. It  is  also  said  to  be  diminished  in  anemia;  but  the 
pallor  which  characterizes  that  disease  is  due  to  a  deficiency 
in  the  number  of  the  red  blood-corpuscles,  as  well  as  to  the 
altered  constituents  of  the  same.  The  temperature 
of  the  body  is  increased  in  diseases  accompanied  with  an 
increased  circulation,  as  in  severe  inflammatory  fevers. 
On  the  other  hand,  it  is  lowered  in  languid  states  of  the 
circulation,  as  in  apnea,  and  in  poisoning  by  some  drugs. 

THE  VASCULAR  SYSTEM  OF  THE  FETUS 

The  arterial  blood  destined  for  the  nutrition  of  the 
fetus  is  carried  from  the  placenta  to  the  fetus,  along  the 
umbilical  cord,  by  the  umbilical  vein.  The  umbilical 
vein  enters  the  abdomen  at  the  umbilicus,  and  passes  up- 
ward along  the  free  margin  of  the  suspensory  ligament  of 
the  liver  to  the  under  surface  of  this  organ,  where  it  gives 
off  two  or  three  branches  to  the  left  lobe ;  one  of  these  is  of 
large  size;  other  branches  are  given  off  to  the  several 
other  lobes  of  the  liver.     At  the  transverse  fissure  of  the 


THE   CIRCULATORY  OR    VASCULAR   SYSTEM      1 39 

liver  the  umbilical  vein  divides  into  two  branches ;  of  these, 
the  larger  joins  the  portal  vein  and  enters  the  right  lobe; 


R.Com.CoiroUdi 

I        L  Com  Cur 01  tot 


R.  SuhelffM 


Sujiei'tor  Vena.  Cava  -  -ffr\ 


L.$u'bclav. 


t/mbiUcu  » 


-Exi  HUiC' 


Placenta, 
Fig.  68. — Diagrammatic  view  of  the  fetal  circulation  (Dorland). 


the  smaller  branch  continues  onward,  under  the  name  of  the 
ductus  venosus,  and  joins  the  left  hepatic  vein  at  the  point 


I40      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

of  junction  of  this  vessel  with  the  inferior  vena  cava. 
The  blood,  therefore,  that  traverses  the  umbilical  vein 
reaches  the  inferior  vena  cava  in  three  different  ways: 
The  greater  quantity  circulates  through  the  liver  with  the 
portal  venous  blood  before  entering  the  vena  cava  by  the 
hepatic  veins;  some  blood  enters  the  liver  directly,  and  is 
also  returned  to  the  inferior  vena  cava  by  the  hepatic 
veins;  the  smaller  quantity  passes  directly  into  the  vena 
cava  by  the  junction  of  the  ductus  venosus  with  the  left 
hepatic  vein. 

In  the  inferior  vena  cava  the  blood  carried  by  the 
ductus  venosus  and  hepatic  veins  becomes  mixed  with 
that  returning  from  the  lower  extremities  and  viscera 
of  the  abdomen.  It  enters  the  right  auricle,  and,  guided 
by  the  Eustachian  valve,  passes  through  the  foramen 
ovale  into  the  left  auricle,  where  it  becomes  mixed  with 
a  small  quantity  of  blood  returned  from  the  lungs  by  the 
pulmonary  veins.  From  the  left  auricle  it  passes  into 
the  left  ventricle,  and  from  the  left  ventricle  into  the 
aorta,  whence  it  is  distributed  almost  entirely  to  the 
head  and  upper  extremities,  a  small  quantity  being  carried 
into  the  descending  aorta.  From  the  head  and  upper 
extremities  the  blood  is  returned  by  the  branches  of  the 
superior  vena  cava  to  the  right  auricle,  where  it  becomes 
mixed  with  a  small  portion  of  the  blood  from  the  inferior 
vena  cava. 

From  the  right  auricle  it  descends  over  the  Eustachian 
valve  into  the  right  ventricle,  and  from  the  right  ventricle 
it  passes  into  the  pulmonary  artery.  The  lungs  of  the 
fetus  are  solid  and  almost  impervious,  hence  only  a  small 
quantity  of  blood  is  distributed  to  them  by  the  right 
and  left  pulmonary  arteries,  and  this  is  returned  by  the 
pulmonary  veins  to  the  left  auricle;  the  greater  part  passes 
through  the  ductus  arteriosus  into  the  commencement  of 
the  descending  aorta,  where  it  becomes  mixed  with  a  small 


THE   CIRCULATORY  OR    VASCULAR   SYSTEM      I4I 

quantity  of  blood  transmitted  by  the  left  ventricle  into 
the  aorta.  Along  this  vessel  it  descends  to  supply  the 
lower  extremities  and  viscera  of  the  abdomen  and  pelvis, 
the  chief  portion  being,  however,  conveyed  by  the  um- 
bilical arteries  to  the  placenta. 

The  placenta  serves  the  double  purpose  of  a  respira- 
tory and  nutritive  organ,  receiving  the  venous  blood  from 
the  fetus,  and  returning  it  again  reoxygenated  and  charged 
with  additional  nutritive  material. 

Changes  at  Birth. — At  birth,  when  respiration  is 
established,  an  increased  amount  of  blood  from  the  pul- 
monary artery  passes  through  the  lungs,  which  now  per- 
form their  office  as  respiratory  organs,  and,  simultane- 
ously, the  placental  circulation  is  cut  off.  The  opening 
between  the  two  auricles  {foramen  ovale)  now  becomes 
gradually  closed  in,  generally  about  the  tenth  day;  val- 
vular folds  now  form  about  the  valvular  opening  or  fora- 
men; sometimes  this  opening  is  persistent  and  never 
closes. 

The  other  parts  of  the  ducts  that  furnish  the  circula- 
tion from  the  after-birth,  through  the  medium  of  the  funis, 
or  cord,  become  obliterated  and  form  attachments  to  the 
several  organs  of  the  internal  viscera. 

The  illustration  (Fig.  68)  will  give  a  fair  idea  of  the 
course  of  the  blood  to  and  from  the  after-birth,  and  of 
the  location  of  the  arterial  structure. 

The  ductus  arteriosus  forms  a  cord  that  connects  the 
left  pulmonary  artery  to  the  concavity  of  the  arch  of  the 
aorta. 

The  umbilical  arteries  form  ligaments  to  the  bladder,  and 
the  umbilical  veins  and  ductus  venosus  become  obliterated 
to  form  fibrous  cords.  The  remains  of  the  umbilical  vein 
forms  the  round  ligament  of  the  liver. 


142      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

REVIEW    QUESTIONS 

What  constitutes  the  circulatory  system? 
Give  the  circulation  of  the  blood. 
What  is  the  heart,  and  where  is  it  located? 
How  is  the  heart  subdivided? 
What  membrane  encloses  the  heart? 

Name  the  valves  contained  within  the  heart,  and  location  of  each. 
What  valves  present  themselves  at  the  beginning  of  the  aorta? 
What  takes  place  when  the  ventricles  contract? 
How  are  the  arteries  distinguished? 
In  what  direction  does  the  arterial  blood  flow? 
Give  a  description  of  the  arteries. 
What  are  the  capillaries? 
What  is  the  aorta,  and  how  is  it  divided? 

What  important  arteries  are  given  off  from  the  abdominal  aorta? 
What  are  the  coronary  arteries?     What  do  they  supply? 
What  important  arteries  pass  to  the  brain? 
What  arteries  supply  the  face  with  blood? 
What  does  the  occipital  artery  assist  in  supplying? 
What  important  structures  does  the  temporal  artery  supply? 
What  artery  pierces  the  dura  mater  and  divides  into  three  branches? 
What  does  the  ophthalmic  artery  supply? 
What  artery  supplies  nutrition  to  the  eye? 
Describe  the  subclavian  artery. 
What  do  you  understand  by  the  vertebral  arteries? 
What  important  artery  do  the  vertebral  arteries  form? 
What  muscles  does  the  internal  mammary  artery  supply? 
Name  the  artery  that  supplies  the  intercostal  spaces  and  pleura. 
What  artery  is  in  the  axillary  space? 
Under  what  bone  do  we  find  the  subclavian  artery? 
Of  what  is  the  radial  artery  a  branch? 
What  artery  lies  on  the  outer  side  of  the  forearm? 
Which  is  the  larger,  the  ulnar  or  the  radial  artery? 
What  forms  the  palmar  arch  in  the  hand? 

What  is  the  abdominal  aorta,  and  what  important  structures  does  this 
supply? 

What  artery  supplies  the  diaphragm? 

What  artery  supplies  the  liver? 

What  important  structure  does  the  splenic  artery  supply? 

Into  how  many  branches  does  the  splenic  artery  divide? 

What  artery  provides  nutrition  to  the  small  intestine? 


THE   CIRCULATORY  OR    VASCULAR   SYSTEM      1 43 

What  artery  supplies  the  upper  part  of  the  duodenum  and  pancreas?  - 

What  other  name  has  the  spermatic  artery? 

What  important  structures  do  the  inferior  mesenteric  artery  supply? 

Name  the  artery  which  supplies  the  kidneys. 

What  artery  provides  nutrition  for  the  pelvic  organs? 

What  artery  passes  down  the  leg,  and  how  is  it  divided? 

What  artery  forms  the  plantar  arch? 

Give  a  description  of  the  pulmonary  artery. 

What  is  the  venous  system? 

What  important  veins  have  we  in  the  neck? 

In  what  direction  does  the  blood  flow  in  the  veins? 

What  are  sinuses,  and  where  are  they  located? 

What  do  veins  contain? 

What  large  vein  in  the  lower  extremity  frequently  becomes  diseased? 

What  forms  the  superior  vena  cava?     The  Inferior? 

What  do  the  azygos  veins  connect? 

What  are  plexuses,  and  where  do  we  find  them? 

Through  what  veins  does  the  blood  from  the  substance  of  the  heart 
return? 

What  makes  up  the  portal  circulation?     Describe  its  location. 

What  do  you  understand  by  the  pulmonary  circulation? 

What  is  the  foramen  ovale? 

Where  would  you  make  pressure  in  a  lacerated  limb  if  an  artery  was 
severed? 

Describe  the  red  corpuscles;  the  white. 

What  is  the  function  of  the  hemoglobin? 

What  is  the  function  of  the  plasma? 

What  is  the  composition  of  the  blood? 

What  is  the  average  quantity  of  blood  in  the  adult? 

Through  what  medium  does  the  fetus  derive  its  nourishment? 

What  is  the  difference  in  the  circulation  of  the  fetus  before  birth  and 
after?     What  takes  place  after  birth? 

What  are  the  changes  that  take  place  in  the  blood? 

On  what  is  the  pulse  dependent? 


CHAPTER    IV 


THE  RESPIRATORY  SYSTEM 

Tun  substances  furnished  to  the  circulation  from  the 
ahmentary  canal  are  in  a  condition  that,  with  reference  to 

the  atmosphere,  will  ad- 
mit of  free  combination 
with  oxygen:  this  latter 
agent  is  quite  necessary 
to  prepare  the  tissues  for 
the  functions  of  assimila- 
tion and  nutrition.  Be- 
sides this,  the  venous 
blood  is  also  charged  with 
carbonated  products  that, 
when  exposed  to  oxygen, 
are  eliminated  and  passed 
off  in  the  form  of  carbon 
dioxid.  To  effect  these 
several  purposes  and  thus 
to  maintain  the  motive 
power  of  the  system, 
eliminating,  at  the  same 
time,  deleterious  sub- 
stances, is  the  function  of 
the  apparatus  of  respira- 
tion. 

The   repiratory    organs 

consist     of     the     larynx, 

trachea,  and  lungs.     The  larynx  is  composed  of  cartilages, 

held  together  by  ligaments,  and  contains  the  vocal  cords. 

144 


Fig.  69. — Interior  of  the  larynx : 
I,  Epiglottis ;  2,  vocal  cord ;  3,  cavity 
of  the  trachea  (after  Testut). 


THE  RESPIRATORY  SYSTEM  1 45 

The  trachea  is  a  membranous  tube  with  cartilaginous 
rings,  which,  upon  its  entrance  into  the  chest,  divides  into 
right  and  left  bronchi.  It  is  about  5  inches  in  length  and 
f  inch  in  diameter. 

The  lungs  are  so  constructed  as  to  receive  a  very  large 
amount  of  atmospheric  air  by  the  most  extraordinary 
mechanism.  The  entire  extent  of  the  respiratory  surface 
in  the  lungs  has  been  estimated  at  100  times  that  of  the 
cutaneous  surface  of  the  body;  the  blood  in  the  pul- 
monary capillaries,  distributed  in  this  large  surface,  and 
being  in  immediate  proximity  to  the  air  in  the  cavity  of  the 
vesicles,  is  placed  under  the  most  favorable  conditions  for 
its  rapid  and  complete  oxygenation. 

Each  pulmonary  vesicle  is  covered  upon  its  exterior 
with  a  close  network  of  capillary  blood-vessels,  which 
penetrate  into  the  septa  between  it  and  the  adjacent 
cavities,  and  which  are  thus  exposed  on  both  sides  to  the 
influence  of  the  atmospheric  air.  The  walls  of  the 
vesicles,  as  well  as  the  interspaces  between  the  lobules,  are 
supplied  with  an  abundance  of  elastic  tissue,  which  gives 
to  the  pulmonary  structure  its  property  of  resiliancy. 

Thus  the  oxygen  of  the  air  combines  with  the  blood, 
while  a  portion  of  the  deleterious  material  also  takes  on 
new  combinations  and  passes  off  with  the  carbon  dioxid. 

THE   LUNGS 

The  lungs  are  situated  in  the  uppermost  portion  of  the 
chest,  and,  when  inflated,  completely  fill  that  cavity. 
They  are  of  irregular  shape  and  two  in  number — one  right 
and  the  other  left.  Bach  is  enclosed  in  a  sac  formed  by 
the  pleural  membrane;  that  portion  of  the  thoracic  cavity 
between  the  right  and  left  pleural  sac  is  known  as  the 
mediastinum.  The  right  lung  is  the  larger  of  the  two,  and 
is  divided  by  two  fissures  into  three  lobes,  whereas  the 
left  lung  is  divided  by  one  fissure  into  two  lobes. 
10 


146      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 


In  their  superior  portion  the  lungs  receive  the  trachea 
or  windpipe,  which  divides  into  the  bronchi,  one  of  which 
goes  to  the  right  lung  and  the  other  to  the  left.  These 
bronchial  tubes  continue  to  divide  and  branch  off  in  the 
parenchymatous  substance  of  the  lungs  until  they  become 
extremely  minute  in  their  ultimate  attenuation.  The 
lungs,  Hke  the  heart,  are  conic   in  shape.     Fig.  70  will 


Larynx. 


Right  common 
ca  rot  id  artery 

Subcla7>ian. 
arteries. 

Innominate' 
artery. 

Arch  of  aorta. 

Right  lung. 

Superior   vena 
cava. 

Right  auricle. 


Left  lung. 

Pulmonary 
artery. 


Heart. 

Coronary 
artery. 


Fig.  70. —  Relation  of  lungs  to  other  thoracic  organs  (Ingals). 


give  some  idea  of  the  shape  of  the  lungs  and  the  position 
of  the  heart;  it  will  also  serve  to  illustrate  the  arrange- 
ment by  which  the  blood  and  the  air  in  the  lungs  become 
exposed  by  contact. 

The  substance  of  the  lungs  is  of  exceedingly  light  and 
spongy  texture,  being  made  up  of  air-cells,  vessels,  and 
tubes  with  their  delicate  walls.  The  color  of  the  lungs 
varies  with  the  age  of  the  subject,  being  a  light  pinkish- 
red  in  youth,  and  becoming  darker,  purplish,  or  mottled. 


THE   RESPIRATORY  SYSTEM  1 47 

in  old  age.  The  weight  of  the  lungs  is  about  42  ounces, 
the  right  lung  being  2  ounces  heavier  than  the  left. 

The  lungs,  like  the  other  organs,  are  supplied  with  nerves 
and  vessels  for  their  nutrition  and  support. 

Respiration. — The  respiration  in  health  is  free,  easy, 
and   noiseless.     The   number   of   respirations   a   minute 


Fig.  71. — Larynx,  trachea,  and  bronchi  (Morrowj. 

varies,  averaging  about  35  during  the  first  year  of  life, 
25  during  the  second,  20  at  puberty,  and  18  in  the  adult. 
The  air  which  is  contained  in  the  pulmonary  lobules  and 
vesicles,  being  used  for  the  purpose  of  arterializing  the 
blood,  becomes  rapidly  vitiated  in  the  process  of  respira- 


148      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

tion,  and  requires  accordingly  to  be  as  rapidly  expelled 
and  replaced  by  a  fresh  supply.  The  exchange  or  reno- 
vation of  the  air  is  effected  by  alternate  movements  of  the 
chest  of  expansion  and  collapse,  which  follow  each  other 
in  regular  succession,  and  which  are  known  as  the  move- 
ments of  inspiration  and  expiration. 

In  inspiration  the  lungs  fill  with  air,  in  expiration  the 
air  is  expelled.  The  movements  of  respiration  are  in- 
voluntary in  character,  and  even  their  acceleration  or 
diminution  is  regulated  by  influences  beyond  our  control. 
We  may  for  a  short  time  control  these  movements,  but 
that  for  a  limited  time  only,  as  the  nervous  impulse  be- 


FlG.  72. — Diagrammatic  representation  of  the  termination  of  a  bronchial 
tube  in  a  group  of  infundibula :  B,  Bronchial  tube ;  LB,  bronchiole :  A^ 
atrium  ;  /,  infundibulum  ;  C,  alveoli  (Nancrede). 


comes  so  very  active  that  we  are  forced  to  breathe.  Then 
again,  if  we  try  to  breathe  more  rapidly  than  the  normal 
respirations,  we  become  fatigued  and  return  to  the  normal 
standard.  Respiration  is,  therefore,  automatic  in  charac- 
ter, as  may  be  noticed  in  persons  during  sleep;  it  is  like 
the  heart  in  that  it  requires  no  effort  upon  our  part  to 
maintain  its  action. 

The  respiratory  movements  vary  according  to  age  in 
sleeping  and  exercise.  There  are  four  pulsations  of  the 
heart  to  one  respiratory  act. 

The  air  which  is  drawn  into  the  lungs  in  respiration  is 


THE  RESPIRATORY  SYSTEM  1 49 

a  mixture  of  oxygen  and  nitrogen  in  the  proportion  of 
about  21  parts  of  oxygen  to  79  parts  of  nitrogen.  It 
also  contains  about  .05  per  cent,  of  carbon  dioxid,  a 
variable  quantity  of  moisture,  and  some  traces  of  am- 
monia. 

If  we  examine  the  air  at  expiration,  after  passing  through 
the  lungs,  we  shall  find  that  it  has  become  altered  in  the 
following  particulars :  First,  it  has  lost  part  of  its  oxygen ; 
second,  it  has  gained  carbon  dioxid,  moisture,  and  or- 
ganic matter. 

The  amount  of  carbon  dioxid  given  off  in  the  expired 
air,  or  the  amount  of  oxygen  that  it  contains,  is  dependent 
upon  the  gross  amount  of  carbohydrates  that  have  been 
consumed  by  the  individual.  Tigerstedt,  in  his  descrip- 
tion of  this  important  action,  says:  "The  percentage  of 
oxygen  in  the  expired  air  is,  of  course,  less  than  that  of  the 
inspired  air,  and,  in  fact,  it  decreases  more,  as  a  rule,  than 
the  per  cent,  of  CO2  (carbon  dioxid)  increases."  When 
carbon  burns  in  oxygen,  the  volume  of  the  gas  does  not 
change.  Since  in  respiration,  however,  the  amount  of 
oxygen  which  has  disappeared  is  greater  than  that  of 
the  carbon  dioxid  formed,  it  follows  that  the  oxygen  is 
used  in  the  body  for  other  oxidations  than  that  of  carbon. 
The  ratio  between  carbon  dioxid  formed  and  oxygen  used, 

^TT ,  is  called  a  respiratory  quottent. 

The  value  of  the  respiratory  quotient  is  very  different 
under  different  circumstances,  and  depends  upon  the  kind 
of  food-stuffs  which  at  the  time  are  being  burned  in  the 
body.  The  carbohydrates  contain  in  their  molecule 
just  as  much  oxygen  as  is  necessary  to  completely  utilize 
their  hydrogen.  The  total  quantity  of  the  inspired  oxygen, 
therefore,  can  be  used  for  oxidation  of  their  carbon. 
The  nurse's  attention  is  directed  to  the  following  classi- 
fication of  the  volumes  of  air  at  rest  and  in  motion  during 


1 50      ANA  TO  MY  AND  PHYSIOL  OG  Y  FOR  NURSES 

pulmonary  ventilation:  (i)  The  residual  air,  or  that  part 
that  cannot  be  expelled  from  the  lungs,  but  remains  after 
a  full  and  forcible  expiration,  averages  120  cubic  inches; 
(2)  the  supplemental  or  reserve  air,  or  that  which  can  be 
expelled  by  forcible  expiration  after  an  ordinary  out- 
breathing,  measures  130  cubic  inches;  (3)  the  breath, 
tidal  or  breathing  air,  averages  26  cubic  inches;  (4)  the 
complementary  air,  or  that  which  can  be  inhaled  after  an 
ordinary  inspiration,  measures  100  cubic  inches.  Thus, 
this  estimate  gives  250  cubic  inches  as  the  average  volume 
of  air  that  the  lungs  contain  after  an  ordinary  inspiration. 

From  what  has  been  said  it  is  apparent  that  the  blood 
is  constantly  exposed  to  the  air  in  the  lungs ;  and  it  would 
appear  that  the  residual  air,  or  that  which  remains  in  the 
lungs  after  the  expiration,  is  most  exposed  to  the  affinities 
in  the  materials  of  the  blood,  and,  in  all  probability,  it  is 
upon  this  portion  that  the  greatest  impression  is  made. 
The  inspiration  replaces  this  residual  air  by  admixture 
with  the  fresh  portions  inspired,  and  some  of  the  expira- 
tions remove  the  mixed  air  so  formed. 

Many  experiments  have  been  tried  to  determine  the 
amount  of  change  of  air  in  the  lungs  produced  by  a  single 
breath.  From  the  nature  of  the  problem  no  method  is 
wholly  satisfactory.  The  one  originally  proposed  by 
"Davy"  is  given  by  Prof.  N.  Kuntz,  of  Leipzig.  It 
consists  of  inhaling  a  known  volume  of  pure  hydrogen, 
and  then  analyzing  the  expired  air.  If  no  mixing  of  the 
hydrogen  with  the  air  already  in  the  lungs  takes  place,  then 
the  expired  gas,  like  the  inspired,  would  be  pure  hydro- 
gen. By  actual  experiment  it  is  found  that,  supposing 
that  500  c.c.  of  pure  hydrogen  are  inhaled,  only  170  c.c. 
of  the  hydrogen  are  exhaled,  the  remaining  330  c.c.  being 
air.  That  is,  330  c.c.  of  the  inhaled  hydrogen  displaces 
the  same  amount  of  air.  If,  now,  it  is  assumed  that  in 
ordinary  breathing  500  c.c.  of  air  are  inhaled,  and  330  c.c. 


THE   RESPIRA  TOR  Y  SYS TEM  1 5  I 

of  this  remain  as  with  the  hydrogen,  and  displaces  a 
similar  amount  of  vitiated  air,  then  the  amount  of  re- 
newal must  be  the  ratio  between  the  air  in  the  lungs  before 
the  inspiration — that  is,  the  reserve  and  the  residual  air 
(3200  CO.),  and  the  fresh  air  (330  c.c.)  remaining  in  the 
lungs  after  each  respiration  (3W0)  =  0.103.  This  has 
been  termed  the  coefficient  of  ventilation,  and  the  case 
given  shows  that  only  about  one-tenth  of  the  air  in  the 
lungs  is  changed  at  each  breath.  The  intermixture  of  this 
fresh  air  in  the  air-passages  is  due  largely  to  the  currents 
produced  by  inspiration,  but  the  residual  air  in  the  alveoli 
and  smallest  air-passages  must  depend  mostly  on  the  jars 
produced  by  the  heart-beats  and  the  pulsation  of  the 
pulmonary  arterioles,  and  also  on  the  ciliary  currents  in 
the  bronchi,  facilitated  by  the  swaying  to  and  fro  of  the 
air  as  the  chest  alternately  expands  and  contracts. 

It  would  seem  reasonable  to  suppose,  therefore,  that  the 
air  in  the  alveoli  remains  of  a  nearly  uniform  percentage 
of  carbon  dioxid,  and  a  less  percentage  of  oxygen  than  the 
expired  air.  The  direct  experiments  of  Wolfberg  and 
others,  however,  show  there  is  but  little  difference  in  the 
composition  of  the  alveolar  air  and  that  which  may  be 
expired  by  a  full  expiration.  This  seems  to  show  that  the 
diffusion  in  the  lungs  is  very  rapid. 

The  trachea  and  bronchi  are  kept  in  a  distended  state, 
and  their  cylindric  form  maintained  by  the  elastic  annu- 
lar cartilages  of  which  the  walls  of  these  tubes  are  con- 
structed. When  in  the  lungs  these  cartilages  are  less 
apparent,  as  the  tubes  ramify  and  diminish,  until  we  find 
the  walls  consisting  simply  of  an  elastic  but  very  delicate 
membrane. 

The  accessory  organs  of  respiration  are  the  diaphragm 
and  the  intercostal  and  abdominal  muscles;  in  difficult 
respiration  other  muscles  of  the  chest  are  called  into  play. 
These  muscles  are  all  under  the  control  of  the  respiratory 


152      ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

center.     The  principal   nerves   concerned   in   respiration 
are  the  phrenic  and  the  pneumogastric  or  par  vagum. 

Each  pleural  cavity  is  a  closed  sac,  one  occupying 
the  right,  the  other  the  left  half  of  the  thorax;  they 
are  perfectly  separate  and  do  not  communicate.  They 
meet  in  the  middle  line  of  the  chest  at  the  upper  part  only, 
just  behind  the  upper  part  of  the  gladiolus  of  the  sternum. 
Lower  down  a  space  (the  mediastinum)  is  left  between 


Fig.  73- — Interior  view  of  the  diaphragm :  1-3,  The  three  lobes  of  the 
central  tendon,  surrounded  by  the  fleshy  fasciculi  derived  from  the  inferior 
margin  of  the  thorax  ;  4,  5,  the  crura;  6,  7,  the  arcuate  ligaments;  8,  aortic 
orifice;  9,  esophageal  orifice;  10,  quadrate  foramen ;  11,  psoas  muscle;  12, 
quadrate  lumbar  muscle. 

them,  which  contains  all  of  the  viscera  of  the  thorax 
excepting  the  lungs. 

The  mediastinum  is  the  space  left  in  the  median 
portion  of  the  chest  by  the  non-approximation  of  the  two 
pleura;  it  extends  from  the  sternum  in  front  to  the  spine 
behind.  It  is  divided  into  an  upper  and  a  lower  portion  : 
the  upper  is  called  the  superior;  the  lower  or  inferior  is 
divided   into    three  subdivisions,  called  respectively  the 


THE   RESPIRATORY  SYSTEM  1 53 

anterior,  middle,  and  posterior  mediastina,  which  have 
their  several  anatomic  boundaries. 

The  ribs  are  elevated  during  inspiration  and  depressed 
during  expiration;  the  chest  is  consequently  expanded 
when  the  air  is  taken  in  and  contracted  when  it  is  given 
out. 

THE   DIAPHRAGM 

The  diaphragm  is  a  firm,  musculofibrous  septum,  situ- 
ated transversely  across  the  cavity  of  the  trunk,  at  the 
lower  margin  of  the  bony  walls  of  the  chest.  It  is  convex 
on  its  upper,  and  concave  on  its  lower,  surface.  By  the 
contraction  of  the  muscle-fibers  in  inspiration,  the  plane  of 
the  diaphragm  becomes  flattened  and  the  lungs  swell  and 
fill  the  enlarged  cavity  of  the  chest,  the  air  rushing  in,  on 
the  principle  of  common  air-pressure. 

REVIEW   QUESTIONS 

What  constitutes  the  respiratory  system? 
What  is  respiration? 
Into  how  many  acts  is  it  divided? 
What  takes  place  in  respiration? 
How  are  the  lungs  divided? 
What  is  the  weight  of  the  lungs? 
Where  are  they  situated? 
What  membrane  surrounds  them? 
Which  lung  is  the  larger? 
What  is  the  trachea? 
How  do  the  bronchial  tubes  divide? 
What  are  the  volumes  of  air  called? 

State  the  average  volume  of  air  taken  in  at  an  ordinary  inspiration. 
Define  reserve  air,  complementary  air,  and  supplementary  air. 
What  are  the  constituents  of  the  inspired  air,  and  also  of  the  expired 
air? 

What  accessory  organs  are  involved  in  respiration? 

Describe  the  pleura. 

What  is  the  mediastinum? 

Describe  the  diaphragm. 

What  nerve  controls  respiration? 


CHAPTER    V 
THE  DIGESTIVE  SYSTEM 

Th^  lungs,  as  we  have  seen  in  the  chapter  on  the 
Respiratory  System,  supply  oxygen  to  the  blood  and 
remove  certain  waste  products.  The  tissues  of  the  body, 
however,  require  many  other  substances  besides  oxygen  to 
maintain  life. 

The  needed  nutrition  is  derived  from  the  food  we  eat. 
The  process  by  which  this  food  is  altered  in  character 
and  prepared  so  as  to  become  available  and  suitable  for 
distribution  to  the  different  parts  of  the  body  is  known 
as  digestion. 

Digestion  is  one  of  the  most  important  functions 
performed  in  the  human  system;  and  any  considerable 
deviation  from  its  regular  action  has  a  ruinous  influence 
upon  the  health.  In  consequence  of  the  great  number  of 
organs  concerned  in  digestion,  the  process  is  subject  to 
frequent  disturbances;  these  occur,  more  or  less,  in  every 
disease  to  which  the  human  frame  is  liable. 

It  is  only  by  considering  the  great  end  of  the  digestive 
process  that  we  can  fully  appreciate  its  vast  importance 
to  the  animal  economy.  By  this  process  our  food  and 
drink  are  prepared  to  yield  their  nutritious  particles  to  the 
blood,  from  which  all  the  other  fluids,  as  well  as  the  solids, 
are  made,  and  upon  which  our  very  existence  depends. 
Whenever,  therefore,  digestion  becomes  enfeebled,  vital- 
ity must  also  become  weakened;  and  a  long-continued 
weakness  of  the  digestive  organs  must  produce  disease, 
and  ultimately  death. 

154 


THE  DIGESTIVE   SYSTEM 


155 


The  Alimentary  Tract. — The  digestion  of  food  takes 
place  in  the  series  of  organs  known  as  the  aUmentary 
tract  or  canal.      This  begins  at  the  mouth,  and  includes 


Salivary  _ 
glands. 


Duodenum. 


Large  intes-, 
tine. 


Salivary 
{Parotid)  gland. 


Rectum. 
Vermiform  appendix. 
Fig.  74-— General  scheme  of  the  digestive  tract,  with  the  chief  glands  open- 
ing into  it  (Stockton). 


the  esophagus,  stomach,  and  intestines,  the  organs  chiefly 
concerned  in  the  digestion  of  food.  It  is  through  this 
canal  that  aliment  or  food  passes,  until,  having  under- 


156      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

gone  various  changes,  it  yields  its  particles  to  the  blood 
in  the  form  of  chyle. 

Mastication. — By  mastication  is  meant  the  tritura- 
tion of  food,  a  process  accomplished  by  the  teeth  and  the 
lower  jaw,  under  the  influence  of  muscular  contraction. 


Fig.  75- — General  plan  of  the  branches  of  the  fifth  pair:  i,  Lesser  root 
of  the  fifth  pair;  2,  greater  root,  passing  forward  into  the  Gasserian  gan- 
ghon ;  3,  placed  on  the  bone  above  the  ophthalmic  division,  which  is  seen 
dividing  into  the  supra-orbital,  lacrimal,  and  nasal  branches,  the  latter  con- 
nected with  the  ophthalmic  ganglion  ;  4,  placed  on  the  bone  close  to  the 
foramen  rotundum,  marks  the  superior  maxillary  division  ;  5,  placed  on  the 
bone  over  the  foramen  ovale,  marks  the  inferior  maxillary  division  (after  a 
sketch  by  Charles  Bell). 


At  the  same  time  the  food  becomes  mixed  with  sali'da  and 
softened.  When  thoroughly  divided,  the  food  presents 
a  greater  surface  for  the  solvent  action  of  the  digestive 
fluids,  thus  aiding  the  general  process  of  digestion. 

The  lower  jaw  is  capable  of  making  a  downward,  an 
upward,    a   lateral,    and   an   anteroposterior   movement, 


THE  DIGESTIVE   SYSTEM  1 57 

dependent  upon  the  construction  of  the  temporomaxillary 
articulation. 

The  movements  of  mastication,  though  originating  in 
an  efifort  of  the  will  and  under  its  control,  are,  for  the  most 
part,  of  an  automatic  or  reflex  character,  taking  place 
through  the  medium  of  the  medulla  oblongata  and  in- 
duced by  the  presence  of  food  within  the  mouth.  The 
nerves  and  nerve-centers  involved  in  this  mechanism  are 
the  following : 

A^ event,  or  Excitor  Nerves:  i.  Lingual  branch  of  the 
fifth  pair.     2.  Glossopharyngeal. 

Eferent,  or  Motor  Nerves:  i.  Third  branch  of  the  fifth 
pair.     2.  Second  hypoglossal.     3.  Facial. 

The  medulla  oblongata  not  only  generates  motor  im- 
pulses, but  co-ordinates  them  in  such  a  manner  that  move- 
ments of  mastication  may  be  directed  toward  the  accom- 
plishment of  a  definite  purpose. 

Insalivation. — Insalivation  is  the  incorporation  of  the 
food  with  the  saliva,  secreted  by  the  parotid,  submaxillary, 
and  sublingual  glands.  This  process  will  be  explained 
in  the  chapter  devoted  to  the  Glandular  System. 

Saliva. — Saliva  is  a  colorless  liquid,  viscid  in  character, 
having  a  specific  gravity  of  1.005;  its  composition  is: 

Water 995-16 

Albuminous  matter 1.34 

Potassium  sulphocyanide 0.06 

Calcareous  magnesium  and  calcareous  phosphates  .    .    .  0.98 

Sodium  and  potassium  chlorides 0.84 

Mixture  of  epithelium      1.62 

1000.00 

The  viscidity  of  the  saliva  is  due  to  the  mucin  which 
it  contains.  Saliva  also  contains  an  enzyme,  called  pty- 
alin,  which  acts  upon  the  starchy  particles  of  food  to  con- 
vert them  into  dextrin  and  sugar;  and,  finally,  by  the 
process  of  hydrolysis  into   dextrin   and   maltose.     The 


158      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

amount  of  saliva  secreted  in  twenty-four  hours  has  been 
estimated  at  about  2\  pounds.     The  secretion  of  saHva  is 


Fig.    76. — Tooth:  a.   Enamel;   b,  dentin;    c,  pulp-cavity;  ^.junction    of 
enamel  and  cementum  ;  <?,  cementum  ;  /,  alveolar  periosteum  (Leroy). 

influenced  through  movements  of  mastication,   by  dry 
substances,  and  by  speaking;  moreover,  saliva  is  poured 


Fig.  TJ. — Diagram  showing  the  temporary  teeth:  a.  Central  incisors; 
b,  lateral  incisors ;  c,  canines ;  d\  anterior  molars ;  e,  posterior  molars 
(J.  P.  C.  Griffith). 


out  in  great  quantities  through  the  influence  of  anything 
which  excites  taste. 


THE  DIGESTIVE   SYSTEM 


159 


The  Teeth. — The  teeth  are  thirty-two  in  number. 
There  are  sixteen  in  each  jaw,  divided  into  four  incisors, 
or  cutting  teeth,  two  canines,  four  bicuspids,  and  six 
molars,  or  grinding  teeth.  Each  tooth  consists  of  a 
crown,  covered  with  enamel,  a  neck,  and  a  root,  sur- 
rounded by  the  crusta  petrosa,  a  thin  layer  of  bone,  em- 


FlG.  78.' — Schema  showing  the  temporary  and  permanent  teeth  in  a  child 
five  years  old  (right  side) :  i,  Temporary  teeth  of  tie  upper  jaw  ;  2,  the  five 
temporary  teeth  of  the  lower  jaw;  3,  3',  permanent  median  incisors;  4,  4', 
permanent  lateral  incisors  ;  5,5',  permanent  canines  ;  6,  6',  the'  four  perma- 
nent bicuspids;  7,  7',  first  molar;  8,  second  molar  of  lower  jaw  in  its  alveo- 
lus (in  the  upper  jaw  the  second  molar  is  not  yet  formed) ;  9,  inferior  dental 
canal ;  10,  orifice  of  inferior  dental  canal  (after  Testut). 


bedded  in  the  alveolar  process  formed  by  the  jaw  bones. 
A  section  through  a  tooth  shows  that  it  is  composed  of 
dentine,  in  the  center  of  which  is  the  pulp  cavity,  contain- 
ing blood-vessels  and  nerves. 

Temporary  Teeth. — The  temporary  teeth  of  children 
are  twenty  in  number — ten  upper  and  ten  lower.  They 
appear  at  about  the  following  ages,  the  lower  teeth  usually 


l6o      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

being   erupted    first.     For   convenience   a   table    is    ap- 
pended : 

The  first  four  central  incisors 5  to    7  months. 

"      "       "    lateral  incisors 6  "  10       *' 

"       "       "    molars Ii   "  16       " 

"       "       "     canines 14  "  21        " 

"       "       "     second  molars 20  "  36       '* 

Those  lettered  a  (Fig.  77)  are  the  central  incisors;  6, 
the  lateral  incisors ;  c,  the  cuspids ;  and  d  and  e,  the  tempo- 
rary molars.  All  but  the  last  {d  and  e)  are  replaced  by 
permanent  teeth  bearing  the  same  names.  In  the  per- 
manent set  the  first  and  second  bicuspids  supplant  the 
temporary  molars.  By  referring  to  the  illustration  (Fig. 
78),  it  will  be  seen  that  while  the  ten  temporary  teeth  are 
visible  in  the  mouth,  the  permanent  teeth  are  being 
formed  within  the  alveolar  margin  of  the  jaws. 

The  permanent  teeth  appear  in  the  following  order: 

The  four  first  molars 5  ^o     6  years. 

two  central  incisors,  lower 6 

**         "  "        upper 7 

four  lateral  incisors 7 

**    first  bicuspids 9 

**    second    **  10 

**    canines Ii 

**    second  molars 12 

"    third  **       (wisdom  teeth)     .  17 

Deglutition. — Deglutition,  or  swallowing,  is  the  act 
by  which  food  is  forced  from  the  mouth  into  the  stomach. 
The  process  may  be  divided  into  three  stages: 

In  the  first  stage,  which  is  entirely  voluntary,  the 
mouth  is  closed  and  respiration  momentarily  suspended. 
The  tongue,  placed  against  the  roof  of  the  mouth,  arches 
upward  and  backward,  and  forces  the  bolus  of  food  into 
the  fauces. 


7 

8 

9 

10 

II 

12 

15 

(C 

23 

« 

THE  DIGESTIVE   SYSTEM 
a        a 


i6i 


' --- :;^-^<^<v 


Fig.  79. — Diagram  showing  the  permanent  teeth  :  a,  Central  incisors;  b, 
lateral  incisors;  c,  canines;  d,  first  bicuspids;  <?,  second  bicuspids;/",  first 
molars;  g,  second  molars ;  h,  third  molars  (J.  P.  C.  Griffith). 


Fig.  80. — The  palate  and  superior  dental  arch  (right  side) :  i,  Median 
incisors;  2,  lateral  incisors;  3,  canine;  4,  first  bicuspid;  5,  second  bicus- 
pids; 6,  first  molar;  7,  second  molar;  8,  wisdom  tooth;  9,  mucous  mem- 
brane of  the  hard  palate  continuous,  behind,  with  that  of  the  soft  palate; 
10,  the  anteroposterior  raphe  of  palate;  11,  pits  on  each  side  of  the  raphe 
perforated  with  the  orifices  of  glands ;  12,  anterior  rugosities  of  the  mucous 
membrane  (after  Testut). 

In  the  second  stage,  which  is  entirely  reflex,  the  palate 
is  made  tense  and  directed  upward  and  backward  by  the 
11 


1 62      ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

levatores  palati  and  tensor  palati  muscles;  the  bolus  is 
grasped  by  the  superior  constrictor  muscle  of  the  pharynx 
and  rapidly  forced  into  the  esophagus.  The  food  is  pre- 
vented from  entering  the  posterior  nares  by  the  uvula  and 
the  closure  of  the  posterior  half-arches;  from  entering  the 
larynx  by  its  ascent  under  the  base  of  the  tongue  and  the 
closure  of  the  epiglottis. 

In  the  third  stage  the  longitudinal  and  circular  muscular 
fibers,  contracting  from  above  downward,  propel  the  bolus 
into  the  stomach. 

THE   ESOPHAGUS   AND   STOMACH 

The  esophagus  is  a  tube  extending  from  the  lower 
end  of  the  pharynx,  or  cavity  of  the  throat,  to  the  stomach, 
passing  through  the  diaphragm.  It  is  9  inches  long,  and 
consists  of  two  layers  of  muscle  lined  with  mucous  mem- 
brane. By  contraction  of  these  muscles  the  food  is  forced 
along  the  tube  to  the  stomach. 

The  stomach  is  situated  in  the  left  side  of  the  upper 
portion  of  the  abdomen.  Its  left  extremity  is  in  contact 
with  the  diaphragm,  and  its  right  is  overlapped  by  the 
liver.  It  has  two  openings:  one  connected  with  the 
esophagus,  called  the  cardiac  orifice;  the  other  connected 
with  the  upper  portion  of  the  intestine,  called  the  pyloric 
orifice. 

It  is  composed  of  three  coats  or  membranes:  the 
exterior  or  serous  coat  invests  every  part  of  this  important 
organ ;  the  middle  coat  is  composed  of  three  layers  of  mus- 
cular fibers,  one  set  of  which  is  arranged  longitudinally, 
the  other,  circularly;  the  interior  coat  is  called  the  mucous, 
and  is  arranged  in  rugae  or  folds.  The  stomach  is  provided 
with  numerous  small  glands  that  secrete  the  gastric 
fluids. 

The  Gastric  Juice. — The  gastric  juice  is  of  an  acid 
character,  and  possesses  very  great  solvent  powers.     The 


THE  DIGESTIVE  SYSTEM 


163 


presence  of  food  in  the  stomach  excites  the  gastric  glands 
to  pour  forth  their  secretion  into  the  stomach.     By  the 


Fig,  81. — Stomach  in  place  after  removal  of  liver  and  mass  of  intestines: 
A,  Diaphragm  ;  B,  B' ,  thoraco-abdominal  wall ;  C,  right  kidney  with  c,  its 
ureter ;  D,  right  suprarenal  capsule ;  E,  left  kidney  with  e,  its  ureter ;  F, 
spleen;  G,  aponeuroses  of  transversales ;  H,H',  quadrati  lumborum  ;  /,  /', 
psoas  muscles;  K,  esophagus;  L,  stomach;  M,  duodenum;  A^,  origin  of 
jejunum,  i,  cardia;  2,  greater  curvature;  3,  lesser  curvature;  4,  great 
tuberosity  or  fundus;  5,  small  tuberosity  or  antrum  of  pylorus  ;  6,  pylorus; 
7,  right  vagus;  8,  left  vagus;  9,  thoracic  aorta;  9',  abdominal  aorta;  10,  in- 
ferior diaphragmatic  arteries;  11,  celiac  axis;  12,  hepatic  artery;  13,  right 
gastro-epiploic;  14,  coronary  artery;  15,  splenic  artery;  16,  x6' ,  superior 
mesenteric  artery  and  vein;  17,  inferior  mesenteric  artery;  18,  spermatic 
artery;  19,  gall-bladder  ;  20,  cystic  duct ;  21,  hepatic  duct ;  22,  inferior  vena 
cava;  23,  portal  vein  ;  24,  great  sympathetic  (Testut). 

violent  mechanical  motions  of  this  organ,  performed  by 
its  muscles  whose  fibers  are  so  diverse  in  direction,  the 


164      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

gastric  juice  becomes  thoroughly  mixed  with  the  food, 
while  the  digestion  of  the  latter  goes  rapidly  on. 


Fig.  82. — Cardiac  glands :  Diagram  showing  the  relation  of  the  ultimate 
twigs  of  the  blood-vessels  (  Fand  A),  and  of  the  absorbent  radicals  {L)  \.o 
the  glands  of  the  stomach,  and  the  different  kinds  of  epithelium — namely, 
above,  cylindrical  cells ;  small  pale  cells  in  the  lumen ;  outside  which  are 
the  dark  ovoid  cells  (Yeo). 

The  gastric  juice  is  a  clear,  colorless  fluid-acid  reaction, 
with  a  specific  gravity  of  1005 ;  its  composition  is  as  follows : 

Water 994.404 

Hydrochloric  acid 0.200 

Organic  matter  (pepsin) 3  I95 

Inorganic  salts 2.201 

1000.000 


It  will  be  noted  that  the  water  forms  the  largest  part 
of  this  fluid,  and  serves  to  hold  the  other  ingredients  in 
solution.  The  hydrochloric  acid  occurs  in  a  free  state, 
and  is  secreted  during  the  digestive  action.     It  varies  in 


THE  DIGESTIVE  SYSTEM  165 

quantity.  The  pepsin  is  associated  with  the  enzymes  of 
the  secretions.  Besides  pepsin,  a  second  ferment,  termed 
rennin,  exists  in  the  gastric  juice,  which  has  the  power  of 
coagulating  the  caseinogen  of  milk.  By  this  action  the 
caseinogen  is  split  into  insoluble  casein  and  soluble  albu- 
min. Calcium  phosphate  is  essential  to  the  action  of  this 
enzyme  (Brubaker). 

The  gastric  glands  are  embedded  within  the  mucous 
membrane  in  enormous  numbers.  They  are  tubular  in 
character,  as  may  be  seen  in  Fig.  82,  which  represents  the 
circulation  within  the  glands,  as  well  as  the  tubules  and 
absorbent  radicals. 

The  principal  action  of  the  gastric  juice  is  to  transform 
the  different  proteid  principles  of  the  food  into  peptones, 
which  is  due  to  the  hydrochloric  acid  and  pepsin ;  when  the 
albumins  come  in  relation  with  the  acid  they  are  converted 
into  parapeptones,  and  in  a  short  period  of  time  they  are 
converted  into  albuminose  with  the  aid  of  pepsin ;  finally, 
they  are  converted  into  peptones  and  absorbed. 

THE  INTESTINES 

The  small  intestine  is  the  narrowest  part  of  the 
digestive  tract,  occupying  the  central  and  lower  parts  of 
the  abdominal  and  pelvic  cavities.  It  is  about  25  feet 
in  length,  and  is  divided,  for  descriptive  purposes,  into 
three  parts — the  duodenum,  jejunum,  and  ileum.  It 
is  suspended  from  the  spine  by  a  fold  of  peritoneum 
called  the  mesentery. 

The  large  intestine  extends  from  the  ileum  to  the 
anus,  and  is  about  5  feet  in  length,  and  is  also  divided,  for 
purposes  of  description,  into  three  parts — ^the  cecum,  colon, 
and  rectum. 

The  Small  Intestine.— The  Duodenum. — ^This  por- 
tion is  somewhat  greater  in  diameter  than  the  remainder 
of  the  small  intestine.     It  received  its  name  from  the  fact 


1 66      ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

that  it  is  about  twelve  finger-breadths  in  length.  Above, 
it  commences  at  the  pylorus,  and  ascends  obliquely  back- 
ward to  the  under-surface  of  the  liver.  It  then  descends 
perpendicularly  in  front  of  the  right  kidney,  and  passes 
transversely  across  the  lower  portion  of  the  spinal  column, 
behind  the  colon,  and  terminates  in  the  jejunum.  The 
ducts  from  the  liver  and  pancreas  open  into  the  perpen- 
dicular portion,  about  6  inches  from  the  stomach. 


Fig.  83. — Duodenum:  a.  Mucosa;  h,  submucosa;  c,  mupcularis  mucosae; 
d,  Brunner's  gland;  e,  crypts  of  Lieberkiihn  (Leroy). 


The  Jejunum. — The  jejunum  is  continuous  with  the 
duodenum,  and  includes  the  upper  two-fifths  of  the  re- 
mainder of  the  small  intestine,  lying  chiefly  in  the  umbili- 
cal region  and  left  iliac  fossa.  It  has  a  pinkish  tinge,  and 
is  thicker  than  the  remainder  of  the  small  intestine. 

The  ileum  is  smaller,  thinner  in  texture,  and  somewhat 
paler  than  the  jejunum.  There  is  nothing  to  mark  the 
termination  of  the  one  or  the  commencement  of  the  other 


THE   DIGESTIVE   SYSTEM 


167 


of  these  portions.  The  ileum  terminates,  at  an  obtuse 
angle,  near  the  right  pelvic  or  haunch  bone  by  a  valvular 
opening  into  the  colon,  which  is  guarded  by  the  ileocecal 
valve.  This  arrangement  prevents  the  passing  of  sub- 
stances from  the  colon  into  the  ileum.  The  jejunum  and 
ileum  are  surrounded  above  and  at  the  sides  by  the  colon. 
The  small  intestine,  like  the, stomach,  has  three  coats 
(some  writers  include  a  fourth,  or  submucous  coat).     The 


Fig.  84. — Mucous  membrane  of  the  jejunum,  highly  magnified  (sche- 
matic):  I,  I,  Intestinal  villi;  2,  2,  closed  or  solitary  follicles;  3,  3,  orifices 
of  the  follicles  of  Lieberkiihn  (Testut). 


inner  or  mucous  coat  is  thrown  into  folds  or  valves.  In 
consequence  of  this  valvular  arrangement  the  mucous 
membrane  is  more  extensive  than  the  other  tissues,  and 
gives  a  greater  extent  of  surface  with  which  the  aliment 
comes  in  contact.  Protruding  from  the  surface  of  the 
mucous  coat  are^n  immense  number  of  projections  which 
are  called  mlli  and  give  the  surface  the  appearance  of 
velvet;  for  this  reasonthis  membrane  is  sometimes  called 
the  villous  coat. 


1 68      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

The  small  intestine  is  beset  with  numerous  small  glands, 
called  Peyer's  glands  or  patches;  they  are  most  numerous 
in  the  lower  two-thirds  of  the  ileum.  These  patches  are 
liable  to  become  ulcerated  in  chronic  dysentery,  and  are  the 
seat  of  the  ulceration  of  the  intestine  that  occurs  in  typhoid 
or  enteric  fever;  in  fact,  this  is  the  supposed  location  and 
seat  of  the  disease. 

The  Large  Intestine.— The  cecum  (cul-de-sac),  or 
blind  pouch,  as  it  is  sometimes  called,  is  the  commence- 
ment of  the  large  intestine.  It  is  closed  at  the  end,  and 
has  projecting  from  its  junction  with  the  ileum  a  slender, 
worm-like  appendage,  called  the  "appendix  vermiformis." 


Fig.  85. — Portion  of  the  wall  of  the  small  intestine,  laid  open  to  show  the 
valvulae  conniventes  (Brinton). 


This  structure  is  situated  in  the  right  iliac  region,  and  is 
about  three  or  four  finger-breadths  in  length.  The  cecum, 
like  the  other  portions  of  the  intestine,  has  a  pouch -like 
arrangement,  caused  by  the  peculiar  position  of  the  fibers 
of  its  muscular  coat. 

The  appendix  vermiformis  is  a  narrow,  blind,  worm- 
like tube,  from  3  to  6  inches  long,  springing  from  the 
lower  and  back  part  of  the  cecum  and  held  in  a  variable 
position  by  a  peritoneal  fold.  Its  function  as  yet  has  not 
been  determined.  It  is  susceptible  to  extensive  inflam- 
mation, resulting  in  many  instances  in  suppuration,  which 
requires  immediate  surgical  intervention  for  the  safety  of 
the  individual. 


THE   DIGESTIVE   SYSTEM 


169 


The  ileocecal  valve  (Fig.  86)  is  formed  by  two  longi- 
tudinal semilunar  folds  of  mucous  membrane  at  the  ter- 
mination of  the  ileum  in  the  cecum,  opening  toward  the 
large  intestine  and  guarding  against  reflux  from  the  large 
into  the  small  intestine. 

The  colon  is  divided  into  three  parts — the  ascending, 
the  transverse,  and  the  descending.  The  ascending  colon 
passes  upward  from  the  right  hip-bone  to  the  under  surface 
of  the  liver.  It  then  bends  inward  and  crosses  the  upper 
part  of  the  abdomen,  below  the  liver  and  stomach,  to  the 


Fig.  86, — The  cecum,   vermitorm  appendix,  and  ileocecal  valve  :   A,  The 
ileocecal  valve  (Campbell). 


left  side,  under  the  name  of  transverse  colon.  At  the 
left  side  it  turns  and  descends  to  the  left  hip-bone,  and  is 
here  called  the  descending  colon.  At  this  point  it  makes 
a  peculiar  curve  upon  itself,  called  the  ''sigmoid  flexure,'' 
from  its  resemblance  to  the  letter  Si  On  its  internal  sur- 
face the  colon  has  many  sac-like  folds,  which  serve  to 
retain  the  contents  in  its  passage  for  a  long  period. 

The  rectum  is  the  lowermost  or  last  portion  of  the  large 
intestine,  and  terminates  in  the  anus;  at  this  point  it  is 
surrounded  by  a  sphincter  or  circular  muscle  that  keeps 
the  orifice  closed  except  during  defecation. 


170      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

Peristalsis  is  the  peculiar  worm-like  motion  of  the 
intestines,  by  means  of  which  its  contents  are  kept  in  mo- 
tion and  become  mixed  with  the  digestive  fluids.  It  is 
produced  by  a  compressing  action  of  the  circular  fibers 
combining  with  a  shortening  action  of  the  longitudinal 
ones. 

Besides  the  organs  just  described  as  being  concerned  in 
the  nutrition  of  the  body,  we  will  consider  here  those 
structures  whose  function  is  the  absorption  of  the  digested 


Fig.  87. — Mucous  membrane  of  the  jejunum  :    i,  Peyer's  patch;   2,  its 
border;  3,  solitary  follicles;  4,  4,  valvulae  conniventes  (Testut). 

food.  These  are  the  lymphatics  of  the  small  intestine, 
known  as  the  lacteals,  the  villi,  and  the  thoracic  duct. 
(See  p.  175.)  Of  these,  the  villi  have  already  been 
described. 

Intestinal  digestion  is  an  important  and  complex 
function,  requiring  several  important  secretions — namely, 
the  pancreatic  juice,  the  bile,  and  the  intestinal  juice,  the 
first  two  of  which  are  the  most  important.  They  mingle 
together  in  the  small  intestine  and  act  upon  the  food,  not 
in  succession,  but  simultaneously. 


THE   DIGESTIVE   SYSTEM  I7I 

The  material  passed  to  the  intestine  during  stomach 
digestion,  called  chyme,  is  slightly  acid  in  reaction.  As 
it  passes  through  the  pylorus  into  the  intestine,  it  excites 
therein  a  secretion  of  the  intestinal  fluids.  These  latter 
have  an  alkaline  reaction,  which  neutralizes  the  substances 
passed  from  the  stomach;  the  nutriment  which  has  not 
been  absorbed  by  the  stomach  is  taken  up  by  the  ab- 
sorbents of  the  intestine  and  sent  to  the  several  parts  of 
the  system,  as  will  be  noted  under  the  Lacteals. 

It  is  supposed  that  in  the  intestines  starchy  substances 
are  converted  into  dextrose.  This  applies  especially  to 
the  conversion  of  cane-sugar,  maltose,  and  lactose  into 
dextrose,  by  which  process  they  are  prepared  for  absorp- 
tion. 

Pancreatic  juice  is  secreted  by  the  pancreas,  the  duct 
of  which  opens  into  the  intestine  (duodenum).  This 
juice  is  a  transparent,  colorless  fluid,  strongly  alkaline, 
with  a  specific  gravity  of  1.040.  Its  composition  is  as 
follows : 

Water 900.76 

Albuminoid  substances 90-44 

Inorganic  salts 8.80 

1000.00 

It  is  the  function  of  the  pancreatic  juice  to  convert 
starch  into  maltose,  and  albumin  into  albumose,  and  finally 
into  peptone ;  the  trypsin  contained  in  it  converts  the  hemi- 
peptones  into  leucin  and  tyrosin.  Pancreatic  juice  has  a 
specific  action  upon  fats,  which  it  emulsifies.  This  action 
is  rapid,  and  depends  upon  the  alkaline  substances  with 
which  it  is  combined.  It  is  supposed  that  the  neutral 
fats  are  acted  upon,  and  converted  into  fatty  acids  and 
glycerin  by  a  ferment  called  steapsin.  The  pancreatic 
juices  increase  the  peristalsis  of  the  intestines  through  the 
glycerin  which  is  produced. 


172      ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

The  individual  actions  of  the  several  ferments  of  the 
pancreatic  juice  are  as  follows:  Amylopsin  is  the  diastic 
ferment  of  the  pancreatic  juice;  it  converts  starches  into 
maltose  and  glucose.  It  transforms  glycogen  into  grape 
sugar,  and  dissolves  cellulose.  This  action  may  take 
place  in  an  alkaline,  neutral,  or  acid  medium. 

Trypsin  converts  albumin  into  peptones  in  alkaline 
medium,  also  in  slightly  acid  media. 

Steapsin  converts  fat  into  fatty  acids  and  glycerin. 

The  bile  is  an  important  secretion,  whose  action  is  to 
prepare  the  food  for  absorption.  It  is  of  a  golden  color, 
and  has  an  alkaline  reaction  and  a  specific  gravity  of  1.020. 
Its  composition: 

Water 859.2 

Sodium  glycocholate  ^  j 
Sodium  taurocholate  / 

Fat      9-2 

Cholestrin 2.6 

Mucus  and  coloring  matter 29.8 

Salts 7.8 

lOOO.O 

The  function  of  the  bile  is  to  assist  in  the  emulsification 
of  the  fats  and  to  aid  in  their  absorption.  It  prevents 
putrefactive  changes  in  the  food.  It  stimulates  the  secre- 
tion of  the  intestinal  glands  and  excites  peristaltic  action 
of  the  bowels.  The  total  amount  secreted  in  twenty-four 
hours  is  estimated  to  be  2 J  pounds. 

The  intestinal  juice  (succus  entericus)  is  secreted  from 
the  small  glands  of  the  intestines  {glands  of  Lieberkuhn) . 
It  resembles  light  Rhine  wine  in  color,  and  is  strongly 
alkaline  from  the  carbonate  of  sodium  it  contains.  The 
constituents  are  albumin  and  mucin. 


THE  DIGESTIVE   SYSTEM  1 73 

THE   LACTEALS 

The  lacteals  are  minute  vessels  that  commence  in  the 
vilU  of  the  small  intestine.  They  pass  between  the  layers 
of  the  mesentery  to  small  glands,  which  they  enter.  The 
first  range  of  glands  collects  many  small  vessels,  and  trans- 
mit a  few  larger  branches  to  a  second  range  of  glands ;  and, 
finally,  after  passing  through  several  successive  ranges  of 
these  glandular  bodies,  the  lacteals,  diminished  in  number 
and  increased  in  size,  proceed  to  the  enlarged  portion  of  the 
thoracic  duct,  into  which  they  open.  They  are  more 
numerous  in  the  upper  portion  of  the  small  intestine. 

The  absorption  of  digested  materials  is  accomplished  by 
the  lymphatics  or  lacteals  of  the  intestines  which  form  part 
of  this  great  system.  The  absorption  takes  place  in  the 
villi,  which  are  part  of  the  mucous  coat  of  the  small  in- 
testine. Passing  through  the  epithelial  layer,  the  lymph 
comes  at  once  in  contact  with  the  capillaries  of  the  vascular 
network. 

Lymphatic  absorbent  vessels  are  found  in  every  part 
of  the  body — in  the  glandular  system,  muscular  organs, 
and  mucous  membranes.  The  lymph  is  a  colorless  or 
slightly  yellowish,  transparent  liquid. 

The  lymphatic  vessels  of  the  intestines  originate  in  the* 
substance  of  the  villi.  They  form  plexuses,  and  continue 
to  build  up  in  size  and  diminish  in  number  until  they 
finally  terminate  in  a  saccular  dilatation  called  the 
receptaculum  chyli,  which  is  the  beginning  of  the  thoracic 
duct. 

The  products  of  digestion,  which  are  taken  up  by  the 
blood-vessels  and  lymphatics  of  the  intestines,  pass  by 
two  different  routes  into  the  general  circulation.  The 
blood  of  the  portal  system,  containing  albuminose,  sugar, 
and  molecular  fat,  is  carried  at  once  to  the  liver,  where 
it  traverses  the  capillary  vessels  of  this  organ  before 
reaching  the  ascending  vena  cava  and  right  side  of  the 


174      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

heart.  The  chyle,  on  the  other  hand,  containing  also  a 
large  portion  of  fatty  ingredients,  passes  by  the  thoracic 
duct,  and  mingles  with  the  return  current  of  the  venous 
blood  in  the  subclavian  vein,  where  it  undergoes  an  im- 
mediate transformation.  In  this  transformation  tie 
fatty  matter  loses  its  distinctive  character  and  is  no  longer 


Fig.  88. — Diagram  showing  the  course  of  the  main  trunks  of  the  absorb- 
ent system :  the  lymphatics  of  lower  extremities  (D)  meet  the  lacteals  of 
the  intestines  (LAC)  at  the  receptaculum  chyli  (R.C.),  where  the  thoracic  duct 
begins.  The  superficial  vessels  are  shown  in  the  diagram  on  the  right  arm 
and  leg  (s),  and  the  deeper  ones  on  the  left  arm  (d).  The  glands  are  here 
and  there  shown  in  groups.  The  small  right  duct  opens  into  the  veins  on 
the  right  side.  The  thoracic  duct  opens  into  the  union  of  the  great  veins  of 
the  left  side  of  the  neck  (t)  (Yeo). 

visible  as  oleaginous  molecules.  The  nutritive  elements  of 
the  food,  prepared  for  absorption  by  the  digestive  process, 
are  taken  up  into  the  circulation  under  the  different  forms 
of  albuminose,  sugar,  and  chyle,  and  accumulate  as  such, 
at  certain  times,  in  the  blood;  but  these  conditions  are 
temporary    and    transitional.     The    nutritive    materials 


THE  DIGESTIVE  SYSTEM 


175 


soon  pass  by  transformation  into  other  forms,  and  become 
assimilated  to  the  pre-existing  elements  of  the  circulating 
fluid.  In  this  way  they  accomplish,  finally,  the  object  of 
digestion,  and  replenish  the  blood  by  a  supply  of  new 
material  from  without. 

THE   THORACIC   DUCT 

The  thoracic  duct  begins  in  the  abdomen  by  a  consider- 
able dilatation  which  is  situated  in  front  of  the  lower 


Vertebral  vein. 
Fig.  89. — Topography  of  the  thoracic  duct  (Zuckerkandl). 


portion  of  the  spinal  column.     From  this  point  it  passes 


1/6      ANATOMY  AND   PHYSIOLOGY  FOR  A'URSES 

through  the  diaphragm,  and  ascends  to  the  lower  part 
of  the  neck.  In  its  ascent  it  hes  anterior  to  the  spine, 
and  by  the  side  of  the  aorta  and  esophagus.  At  the  lower 
part  of  the  neck  it  makes  a  sudden  turn  downward  and 


Thyroid, 
gland. 


Longus  colli  muscle. 


/  \  Axillary 
lymphatic 
trunk. 


Internal  jugular  vein. 
Fig.  90- — Topography  of  the  thoracic  duct  (^uckerkandl). 

forward,  and  terminates  by  opening  into  the  left  subcla- 
vian vein.  The  thoracic  duct  is  equal  in  diameter  to  a 
goose-quill,  and  at  its  termination  is  provided  with  a  pair 
of  semilunar  valves,  which  prevent  the  admission  of  venous 
blood. 


i 


THE  DIGESTIVE  SYSTEM 


17; 


REGIONS    OF    THE    ABDOMEN    AND    THEIR 
CONTENTS 

By  referring  to  the  illustration  (Fig.  91),  you  will  ob- 
serve that  the  abdomen  is  divided  into  nine  regions; 
these  are:  The  right  hypochondriac,  right  lumbar,  right 
inguinal,  epigastric,  umbilical,  hypogastric,  left  hypo- 
chondriac, left  lumbar,  and  left  inguinal.  The  division, 
as  will  be  seen  from  the  illustration,  is  made  by  draw- 


FlG  91. — Imaginary  lines  drawn  upon  the  surface  of  the  abdomen  divid- 
ing it  into  regions  :  i,  Right  hypochondriac  region  ;  2,  epigastric ;  S,  left 
hypochondriac  ;  4-  right  lumbar;  5,  umbilical ;  6,  left  lumbar;  7,  right  iliac  ; 
8,  hypogastric  ;  9,  left  iliac  (Chapman). 


ing  an  imaginary  line  horizontally  between  the  car- 
tilages of  the  ninth  ribs;  another  between  the  crest  of 
the  ilia;  and  two  vertical  lines  from  the  cartilages  of 
the  eighth  ribs  to  the  center  of  Poupart's  ligament. 

The  right  hypochondriac  region  contains  the  right 
lobe  of  the  liver,  the  gall-bladder,  the  duodenum,  the 
hepatic  flexure  of  the  colon,  the  upper  part  of  the  right 
kidney,  and  the  right  suprarenal  capsule. 

12 


178      ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

The  epigastric  region  contains  the  right  two-thirds 
of  the  stomach,  the  left  lobe  of  the  liver,  the  celiac  axis,  the 
solar  plexus,  the  pancreas,  and  part  of  the  aorta,  inferior 
vena  cava,  vena  azygos,  and  thoracic  duct. 

The  left  hypochondriac  region  contains  the  splenic 
end  of  the  stomach,  the  spleen,  the  tail  of  the  pancreas, 
the  splenic  flexure  of  the  colon,  the  upper  half  of  the  left 
kidney,  and  its  suprarenal  capsule. 

The  right  lumbar  region  contains  the  ascending 
colon,  the  lower  half  of  the  right  kidney,  and  part  of  the 
small  intestine. 

The  umbilical  region  contains  the  transverse  colon, 
the  transverse  duodenum,  part  of  the  great  omentum  and 
mesentery,  and  part  of  the  small  intestine. 

The  left  lumbar  region  contains  the  descending 
colon,  the  lower  half  of  the  left  kidney,  and  part  of  the 
small  intestine. 

The  right  inguinal  region  contains  the  right  ureter, 
the  cecum,  the  appendix  vermiformis,  and  the  spermatic 
vessels  of  that  side. 

The  hypogastric  region  contains  part  of  the  small 
intestine,  the  bladder  in  children  (and  when  distended, 
in  adults),  and  the  uterus  during  pregnancy. 

The  left  inguinal  region  contains  the  left  ureter, 
the  spermatic  vessels,  and  the  sigmoid  flexure  of  the  colon. 


REVIEW    QUESTIONS 


^-^-^    -    -    1.a\><> 


What\^]^^s  constitute  the  digestive  system? 
.  What  is  mastication? 

v)*"-*"*^       What  organs  are  brought  into  action  in  the  mastication  of  foods? 

What  nerve  controls  this  action? 

What  is  the  saliva? 

What  important  enzyme  does  the  saliva  contain? 

How  many  temporary  teeth  are  there? 

At  what  ages  are  they  erupted? 

Give  the  number  of  permanent  teeth. 


^Vv 


THE  DIGESTIVE   SYSTEM  1 79 

What  is  deglutition? 

What  is  the  stomach? 

What  important  openings  does  the  stomach  contain? 

How  many  coats  has  the  stomach? 

What  is  the  gastric  juice? 

What  is  its  composition? 

Name  the  several  enzymes  of  same,  and  state  their  several  actions. 

State  the  divisions  of  the  small  intestine. 

Give  the  location  of  the  duodenum  of  the  jejunum,  of  the  ileum. 

What  valve  is  situated  at  the  junction  of  the  small  with  the  large 
intestine? 

What  patches  are  found  in  the  lower  portion  of  the  ileum? 

What  disease  is  particularly  apt  to  affect  these  glands? 

What  secretions  are  concerned  in  the  digestive  process? 

What  is  the  pancreatic  juice? 

What  is  the  composition  of  the  pancreatic  juice? 

Describe  the  individual  action  of  the  several  ferments  of  the  pancre- 
atic juice. 

What  is  the  bile,  and  from  what  source  is  it  derived? 

What  is  the  action  of  the  bile? 

State  the  estimated  amount  secreted  in  twenty-four  hours  and  give 
the  color  of  the  bile. 

What  is  produced  when  the  intestines  are  inflamed? 

What  are  the  glands  of  Lieberkiihn? 

What  secretions  are  formed  from  these  glands? 

How  is  the  large  intestine  divided  as  to  name? 

What  important  flexure  is  there  in  the  descending  portion? 

What  is  the  rectum?     In  what  does  it  terminate? 

What  do  you  understand  by  peristaltic  movements? 

What  are  lymphatics? 

Where  is  the  thoracic  duct  located? 

What  is  provided  at  its  termination?     Why? 

Where  do  the  lacteals  originate? 

Through  what  route  do  the  products  of  digestion  pass  in  entering 
the  circulation? 

What  are  the  lacteals? 

Should  digestion  be  interfered  with?     What  would  be  the  result? 

What  are  the  regions  of  the  abdomen? 

State  as  nearly  as  possible  what  important  organs  are  located  in  the 
several  divisions. 


CHAPTER    VI 

THE  EXCRETORY   SYSTEM 

W^  have  considered  the  circulatory,  the  respiratory, 
and  the  digestive  systems,  with  the  various  chemic 
substances  that  are  required  to  maintain  the  Hfe,  growth, 
and  activity  of  the  body.  These  substances,  entering 
the  current  of  the  blood,  are  carried  to  all  organs  and  tis- 
sues, and  are  incessantly  combining  with  the  chemic  sub- 
stances of  which  these  tissues  are  composed.  These  com- 
binations are  not  dependent  upon  chance;  each  tissue  has 
a  special  affinity  for  the  chemic  substance  in  the  blood 
that  it  requires  for  its  own  growth  and  special  form  of 
activity;  for  example,  the  secretory  cell  of  the  liver  selects 
substances  from  which  it  can  elaborate  bile  and  glycogen ; 
the  muscle-fiber  assimilates  those  that  will  promote  the 
changes  upon  which  the  power  of  contractility  depends. 

We  know  that  the  proteid  compounds  contain  the  most 
essential  elements  for  the  formation  of  all  forms  of  tissue, 
and  that  phosphate  of  lime  is  a  necessary  factor  in  the 
hardening  of  bone,  but  we  are  utterly  ignorant  of  the  proc- 
ess by  which  each  tissue  element  is  enabled  to  select  the 
particular  substance  it  needs  and  to  reject  that  which  it 
does  not  require. 

Metabolism. — Our  bodies  are  masses  of  changing 
atoms,  some  of  which,  we  may  say,  are  on  the  "up  grade," 
to  construct  the  various  tissues,  and  some  on  the  "down 
grade,"  to  form  the  waste  matters  that  are  the  final  prod- 
ucts of  the  tissues'  activity.  These  changes,  which  are 
going  on  incessantly  while  life  lasts,  are  described  under 
180 


THE  EXCRETORY  SYSTEM  l8l 

the  general  term  metabolism;  the  constructive  changes  are 
termed  anabolic;  the  destructive,  katabolic. 

The  final  products,  then,  of  the  metabolism  of  the  body 
will  be  certain  waste  matters;  we  shall  now  proceed  to 
describe  the  mechanism  of  the  organs  by  means  of  which 
these  waste  products  are  eliminated  from  the  body. 

The  Elimination  of  Waste  Products. — In  passing 
through  the  blood  and  tissues  of  the  body  the  proteids, 
fats,  and  carbohydrates  are  transformed  into  urea,  or 
some  allied  product,  carbon  dioxid,  and  water,  the  nitro- 
gen of  the  urea  being  supplied  by  the  proteids  alone. 
Many  of  the  proteids  contain  sulphur,  and  in  some  phos- 
phorus in  some  combination  is  also  present;  many  of  the 
fats  taken  as  food  contain  phosphorus.  By  oxidation 
these  elements  are  converted  into  phosphates  and  sul- 
phates, and  are  excreted  in  company  with  other  salts  of 
the  body. 

Broadly  speaking,  then,  the  waste  products  of  the  body 
consist  of  urea,  carbon  dioxid,  salts,  and  water.  These 
leave  the  body  by  one  of  three  main  channels — ^the  lungs 
the  skin,  or  the  kidneys.  A  portion,  it  is  true,  leaves 
the  body  by  the  bowels,  for,  as  we  have  seen,  the  feces 
contain,  besides  undigested  portions  of  food,  substances 
that  have  been  excreted  into  the  bowels,  and  are  therefore 
waste  products;  this  amount  is,  however,  very  small,  and, 
except  in  diseased  conditions,  is  not  of  any  special  import- 
ance. The  waste  matter  discharged  relatively  by  the 
lungs,  skin,  and  kidneys  may  be  stated  to  be  as  follows : 

By  the  lungs:  The  greater  part  of  the  carbon  dioxid;  a 
considerable  quantity  of  water. 

By  the  skin:  A  variable  but,  on  the  whole,  large  quantity 
of  water,  a  little  carbon  dioxid,  and  a  small  amount  of  salts. 

By  the  kidneys:  All  or  nearly  all  the  urea  and  allied 
bodies;  the  greater  part  of  the  salts;  a  large  amount  of 
water  and  a  very  small  quantity  of  carbon  dioxid. 


1 82      ANJTOAIV  AND  PHYSIOLOGY  FOR  NURSES 

Having  studied,  in  a  previous  chapter,  the  mechanism 
by  which  the  lungs  relieve  the  blood  of  carbon  dioxid 
and  water,  it  now  remains  for  us  to  consider  the  excretory 
mechanism  of  the  kidneys  and  of  the  skin.  The  former 
excretes  the  urine,  while  the  other  urinary  organs,  the 
ureters,  bladder,  and  urethra,  collect  the  urine  and  effect 
its  exit  from  the  body.     The  mechanism  by  which  the 


Fig.  92. — Diagram  of  the  relation  of  kidney  to  viscera,  spine,  and  surface 
points  {American  Text-Book  of  Surgery). 


skin  excretes  waste  products  in  the  form  of  perspiration 
will  be  considered  further  on. 


THE    KIDNEYS 

The  kidneys  are  two  tubular,  secreting  glands,  placed 
at  the  back  of  the  abdominal  cavity,  one  on  each  side  of 
the  lumbar  vertebrae.  They  are  bean  shaped,  the  con- 
cave side  being  directed  toward  the  spine,  and  the  convex 
side  outward.  Each  kidney  is  about  4  inches  long,  2 
inches  broad,  i  inch   thick,  weighs  from  5  to  6  ounces. 


THE  EXCRETORY  SYSTEM 


183 


and  extends  from  the  eleventh  dorsal  to  the  third  lumbar 
vertebra.  The  right  kidney  is  a  little  lower  than  the  left, 
in  consequence  of  the  large  space  occupied  by  the  liver. 
The  kidneys  are  covered  by  a  tough  envelope  of  fibrous 
tissue  called  the  capsule  of  the  kidney,  and  are  usually 
embedded  in  a  considerable  quantity  of  fat. 


Fig.  93. — Kidney,  longitudinal  section,  exhibiting  general  relations  of 
microscopic  details  (after  Piersol) :  A,  Renal  artery;  £^,  ureter;  C,  one  of 
the  calices,  into  which  a  papilla  projects;  i,  cortex  containing  labyrinth  (/) 
and  medullary  rays  (w)  ;  2,  medulla ;  M,  Malpighian  pyramids,  some  ob- 
liquely cut  at  3,  3  ;  3,  boundary  layer ;  B,  columns  of  Bertini ;  4,  masses  of 
adipose  tissue  ;  5,  5,  branches  of  renal  artery  (after  Henle). 

Structure  of  the  Kidneys.— The  kidney  is  made  up 
of  an  outer  part,  the  cortex,  and  an  inner  part,  the  medulla. 
Its  substance  is  composed  of  a  mass  of  uriniferous  tubules 
and  Malpighian  bodies.  The  Malpighian  bodies  (Fig.  94) 
are  located  in  the  cortex  of  the  kidney  near  the  surface, 
and  consist  of  a  tuft  of  blood-vessels,  the  glomerulus,  and 
an  expansion  of  the  uriniferous  tubule,  which  forms  a 
covering  about  the  glomerulus.     The  uriniferous  tubules, 


1 84      ANA  TOM  V  AND  PHYSIOL  OGY  FOR  NURSES 


Fig.  94. — A  Malpighian  body  or  corpuscle  ;  a.  Afferent  artery ;  e,  efferent 
vessel ;  c,  capillaries  ;  k,  commencement  of  uriniferous  tubule  ;  h,  uriniferous 
tubule  (Leidy). 


Inner  stratum  of  cortex,  without 
Malpighian  corpuscles. 


}^    Subscapular  layer 
'  without       Mal- 

pighian corpus- 
cles. 


^)   Cortex, 


Fig.  95. — Uriniferous  tubule. 


THE  EXCRETORY  SYSTEM 


185 


after  leaving  the  Malpighian  body,  twist  and  turn  several 
times,  finally  emptying  into  the  ureter  (Fig.  95). 

By  the  arrangement  of  blood-vessels  described  above, 
the  arterial  blood  is  brought  directly  to  the  glomerulus. 
It  is  during  its  circulation  through  the  glomerulus  that  the 
blood  gets  rid  of  some  of  its  fluid  constituents,  while  the 


Fig.  96. — The  kidneys,  ureters,  bladder,  and  their  vessels  viewed  from 
behind:  R,  Right  kidney;  U,  ureter;  A,  aorta;  Ar,  right  renal  artery;  Ve, 
vena  cava  inferior ;  Vr,  right  renal  vein  ;  Vu,  bladder ;  Ua,  commencement 
of  urethra  (Campbell). 


waste  products  are  excreted  by,the  uriniferous  tubules. 
The  waste  matter,  in  the  form  of  water,  carbon  dioxid, 
salts,  and  urea,  passes  into  the  tubules,  and  is  passed  off 
from  the  kidney  in  the  form  of  urine. 

The  Blood=supply  of  the  Kidneys. — For  an  organ 
of   its   size,    the   kidney    is    abundantly    supplied    with 


1 86      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

blood.  This  is  derived  from  the  renal  artery,  which,  as 
we  have  seen  in  the  description  of  this  structure  in  a 
previous  chapter,  comes  directly  from  the  abdominal 
aorta. 

THE   URETERS 

The  ureters  are  the  excretory  ducts  of  the  kidneys. 
They  arise  in  the  middle  of  the  concave  side,  or  hilus, 
of  each  kidney,  and  proceed  obliquely  downward  and  in- 
ward through  the  lumbar  region  of  the  abdomen  into  the 
pelvis,  to  open  obliquely  by  two  constricted  orifices  into 
the  base  of  the  bladder.  Each  ureter  is  from  i6  to  i8 
inches  long,  of  the  diameter  of  a  goose-quill,  and  is  made 
up  of  muscular  tissue  lined  by  mucous  membrane.  The 
muscular  coat  is  arranged  in  two  layers — an  outer  cir- 
cular and  an  inner  longitudinal  layer.  Outside  the 
muscular  coat  is  a  layer  of  fibrous  connective  tissue,  carry- 
ing the  blood-vessels  and  nerves  with  which  the  tube  is 
supplied. 

THE   BLADDER 

The  bladder  is  a  musculomembranous  sac  that  serves 
as  the  reservoir  for  the  urine.  It  is  situated  in  the  pelvic 
cavity,  behind  the  pubes,  and  is  held  in  position  by  liga- 
ments. During  infancy  it  is  conic  in  shape,  and  pro- 
jects above  the  upper  border  of  the  pubes  into  the  hypo- 
gastric region.  In  the  adult,  when  quite  empty,  it  is 
deeply  placed  in  the  pelvis.  When  slightly  distended  it 
has  a  rounded  form,  but  when  greatly  distended  it  is 
ovoid  in  shape,  and  rises  to  a  considerable  height  in  the 
abdominal  cavity.  When  moderately  distended,  it  meas- 
ures about  5  inches  in  length  and  3  inches  across.  The 
amount  of  urine  which  the  bladder  ordinarily  contains  is 
about  I  pint. 

In  structure,  the  bladder  consists  of  involuntary  mus- 
cular tissue  lined  by  a  strong  mucous  membrane,  and 


THE  EXCRETORY  SYSTEM  1 8/ 

covered  partially  by  a  serous  coat  derived  from  the 
peritoneum.  The  muscular  coat  has  three  layers,  the 
principal  fibers  of  which  run  longitudinally  and  circu- 
larly, the  circular  fibers  being  collected  into  a  layer  of 
some  thickness  around  the  constricted  portion  or  neck, 
where  the  bladder  becomes  continuous  with  the  urethra. 
These  circular  fibers  around  the  neck  form  a  sphincter 
muscle  that  normally  is  in  a  state  of  contraction,  relaxing 
only  at  intervals,  when  the  accumulation  of  urine  within 
the  bladder  renders  its  expulsion  necessary. 

The  Urethra. — The  urethra  is  a  narrow,  membran- 
ous canal,  about  ij  inches  in  length  in  the  female,  and 
extending  from  the  neck  of  the  bladder  to  the  external 
orifice,  or  meatus  urinarius.  It  is  situated  beneath  the 
symphysis  pubis,  and  is  embedded  in  the  anterior  wall  of 
the  vagina.  It  runs  obliquely  downward  and  forward,  its 
course  being  slightly  curved,  the  concavity  directed  for- 
ward and  upward.  While  it  admits  of  considerable  di- 
latation, its  normal  diameter  is  about  \  inch.  It  is 
lined  by  a  mucous  coat  that  is  continuous,  externally, 
with  that  of  the  vulva,  and,  internally,  with  that  of  the 
bladder.  The  external  muscular  coat  is  also  continuous 
with  that  of  the  bladder,  but  between  the  mucous  and 
muscular  coats  is  a  layer  of  thin,  spongy  tissue,  containing 
a  network  of  large  veins.  In  the  male,  the  urethra  ex- 
tends from  the  neck  of  the  bladder  to  the  meatus  urinarius 
at  the  end  of  the  penis,  measuring  8  or  9  inches.  It  is 
divided  into  a  prostatic  portion,  a  membranous  portion,  and 
a  spongy  portion.  The  latter  portion  is  the  longest,  being 
contained  in  the  corpus  spongiosum  of  the  penis  (see  Fig. 
156).  (By  referring  to  the  illustrations.  Figs.  145,  146, 
the  structures  that  make  up  the  urinary  organs  may  be 
clearly  seen.) 

Micturition. — This  act  is  normally  caused  by  the 
accumulation  of  urine  within  the  bladder.     The  accumu- 


1 88      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

lation  stimulates  the  muscular  walls  to  contract,  the  resist- 
ance of  the  sphincter  at  the  neck  of  the  bladder  is  over- 
come, and  the  urine  is  ejected  through  the  urethra. 

Involuntary  micturition  may  occur  as  a  result  of  spinal 
injury,  involving  the  nerve-centers  that  send  nerves  to  the 
bladder.  It  may  also  be  due  to  a  want  of  tone  in  the  mus- 
cular walls,  or  it  may  result  from  abnormal  irritation. 

The  Urine. — General  Character  of  the  Urine. — 
Normal  urine  may  be  described  as  a  transparent,  watery 
fluid,  of  a  pale  yellow  color,  acid  reaction,  a  specific  gravity 
of  loiS  to  1 020,  and  possessing  an  odor  that  can  only  be 
described  as  characteristic  or  urinous.  Bach  one  of  these 
characters  is  subject  to  some  variation  within  the  limits 
of  health  as  well  as  in  disease. 

The  transparency  of  urine  may  be  diminished  in  health 
by  the  presence  of  mucus  derived  from  the  genito-urinary 
tract,  or  by  the  deposits  of  salts.  In  disease  the  urine 
may  become  clouded  by  the  presence  of  pus. 

The  color  of  urine  depends  mainly  upon  the  amount 
of  water  it  contains ;  also  upon  a  diminution  or  increase  of 
the  coloring  matter.  In  hysteria,  in  which  the  urine  is 
copious  in  amount,  the  color  is  very  light,  while  in  fevers, 
in  which  it  is  scanty,  the  color  is  very  high.  It  may  take 
on  abnormal  color  as  the  result  of  the  ingestion  of  certain 
foods  or  medicine,  or  this  may  be  due  to  a  diseased  condi- 
tion. 

The  reaction  of  urine  should  always  be  tested  from  a 
collection  of  urine  passed  during  twenty-four  hours,  for  it 
is  affected  by  diet  and  exercise;  the  reaction  of  mixed  urine 
is  normally  acid. 

The  specific  gravity  of  urine  depends  upon  the  amount 
of  solid  waste  matter  present  in  the  urine.  In  health  it 
may  vary  from  1015  to  1025.  When  the  solids  are  dis- 
solved in  a  large  amount  of  water,  the  specific  gravity  will 
naturally  be  lower  than  when,  from  a  deficiency  of  water, 


THE  EXCRE  TOR  Y  S  YSTEM  1 89 

the  urine  is  more  concentrated.  In  the  disease  known  as 
diabetes  melUtus  the  specific  gravity  of  the  urine  is  con- 
siderably heightened,  owing  to  the  presence  of  sugar. 
The  specific  gravity  is  of  greatest  value  when  it  is  obtained 
from  a  twenty-four-hour  collection. 

The  Composition  of  Urine. — The  chief  constituents  of 
normal  urine  are  water,  urea,  uric  acid,  coloring  matter, 
and  salts.  Of  these  constituents,  urea  is  by  far  the  most 
important,  for  it  is  the  chief  waste  product  of  the  body. 
To  eliminate  urea  is  the  special  work  of  the  kidneys,  and  if, 
for  any  reason,  they  fail  to  do  their  work,  the  accumula- 
tion of  the  urea  in  the  system  eventually  leads  to  the  ter- 
mination of  life.  Urea  is  the  final  product  of  all  proteid 
substances,  and,  consequently,  a  diet  rich  in  proteids  will 
increase  the  amount  of  urea  in  the  system. 

Of  the  salts,  sodium  chlorid  occurs  in  the  largest  quan- 
tity. In  certain  inflammatory  diseases,  in  which  it  is 
needed  by  the  blood,  it  sometimes  disappears  temporarily 
from  the  urine. 

When  the  kidneys  are  diseased,  it  is  customary  for 
physicians  to  lighten  their  work  as  far  as  possible  by 
regulating  the  diet. 

The  chief  abnormal  constituents  that  are  liable  to  appear 
in  the  urine  are  albumin  and  sugar;  the  former  gives  rise 
to  a  condition  known  as  albuminuria;  the  latter,  to  the 
disease  called  diabetes. 

The  normal  quantity  of  urine  passed  in  twenty-four 
hours  is  from  40  to  50  ounces,  or  about  3  pints.  This 
amount  will  vary  in  health  according  to  the  condition  of 
the  skin  and  the  amount  of  fluid  taken  into  the  body. 
The  excretion  of  water  by  the  kidneys  is  closely  related  to 
a  similar  process  conducted  by  the  skin.  When  the  body 
is  exposed  to  cold  the  blood-vessels  in  the  skin  are  con- 
stricted, and  the  discharge  of  water  in  the  form  of  sweat  is 
checked;  at  the  same  time  the  blood-vessels  of  the  kidneys 


190      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

are  dilated,  there  is  a  full  and  rapid  stream  of  blood  through 
the  glomeruli,  and  an  increased  flow  of  urine  results. 
On  the  other  hand,  when  the  body  is  exposed  to  warmth, 
the  cutaneous  vessels  are  widely  dilated  and  free  per- 
spiration occurs,  while  the  renal  vessels  being  constricted, 
only  a  small  and  slow  stream  of  blood  trickles  through  the 
glomeruli,  and  the  urine  that  is  secreted  is  scanty  in 
amount. 

The  effect  of  secretion,  however,  is  governed  largely 
by  the  amount  of  fluid  absorbed  through  the  alimentary 
canal;  an  increased  secretion  of  water  always  follows  an 
ordinary  meal,  and  when  large  quantities  of  water  are 
drunk,  the  amount  of  urine  is  correspondingly  increased. 

THE   SUPRARENAL   CAPSULES 

The  suprarenal  capsules  are  two  small,  flattened  bodies, 
of  a  yellowish  color,  one  situated  immediately  above  each 
kidney.  Having  no  excretory  duct,  they  are  usually 
classified  with  the  ductless  glands.  Each  organ  is  invested 
by  a  fibrous  capsule  that  sends  septa  into  the  glandular 
substance;  these  septa  form  a  framework  for  the  soft, 
pulpy  substance  of  the  gland,  and  within  the  spaces  of  this 
framework  are  groups  of  cells. 

The  suprarenal  capsules  are  abundantly  supplied  with 
blood-vessels,  nerves,  and  lymphatics,  and  contain  re- 
markable coloring  matters.  When  these  organs  become 
diseased,  the  skin  frequently  becomes  "bronzed,"  from  an 
increase  of  pigment  or  coloring-matter.  Their  special 
function  is  as  yet  unknown. 

THE  SKIN 

Having  described  the  mechanism  by  which  the  lungs 
eliminate  carbon  dioxid  and  water  from  the  body,  and  the 


THE   EXCRETORY  SYSTEM  I9I 

manner  in  which  the  kidneys  relieve  it  of  urea,  salts,  and 
water,  it  now  remains  for  us  to  consider  the  part  played 
by  the  skin  in  eliminating  water  and  a  certain  amount  of 
carbon  dioxid  and  salts. 

The  skin,  unlike  the  kidneys,  is  not  set  apart  for  the 
performance  of  one  special  function.  It  is  not  only  an 
important  excretory  organ,  but  also  an  absorbing  organ; 
it  is  likewise  the  principal  seat  of  the  sense  of  touch,  and 


Fig.  97-— Vertical  section  of  skin :  sbg.  Sebaceous  glands ;  ep,  epidermis ; 
h,  hair;  d,  derma  (Fox). 


also  serves  as  a  protective  covering  for  the  underlying 
tissues.  The  skin,  like  the  mucous  membrane,  consists 
of  two  distinct  layers — an  epithelial  covering  and  a 
connective-tissue  basis.  The  epithelium  is  stratified, 
and  is  called  the  epidermis  or  scarf-skin;  the  con- 
nective-tissue layer  is  called  the  derma  (true  skin)  or 
corium. 

The  epidermis  is  composed  of  layers    of    cells,   the 


192      ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

deeper  of  which  are  soft  and  protoplasmic,  while  the 
superficial  layers  are  hard  and  horny.  Between  the  two 
layers  is  a  fairly  distinct  line  of  granular-looking  cells,  the 
granules  in  which  have  been  thought  to  form  the  homy 
matter  in  the  superficial  cells.  In  the  colored  races  the 
single  layer  of  elongated  cells  next  to  the  corium  contains 
pigment-granules . 

The  epidermis,  which  throughout  the  body  is  of  homy 
consistence,  but  so  thin  as  readily  to  admit  of  flexibility, 
is  on  the  ends  of  the  fingers  replaced  by  a  thicker  and 
more  permanent  texture  of  horny  substance,  called  the 
nails  (clavus). 

In  the  palms  of  the  hands  and  on  the  soles  of  the  feet 
the  skin  is  thickened  and  more  firm,  according  as  the  parts 
are  exposed  to  friction  or  wear. 

The  outer  surface  of  the  skin  is  covered  by  numer- 
ous small  eminences  or  papillcB,  which  are  the  termina- 
tions of  the  nerves  and  vessels,  each  papilla  containing  a 
nerve  and  one  or  more  vessels. 

The  corium,  as  has  been  said,  possesses  great  sensi- 
bility, and  is  commonly  regarded  as  the  starting-point  of 
the  nervous  system  to  palpable  feeling.  It  is,  therefore, 
very  largely  supplied  with  nerves,  and  is  also  well  furnished 
with  blood. 

The  outer  layer,  or  epidermis,  possesses  no  sensibility, 
and  yet,  being  extremely  thin  and  delicate,  it  offers  but 
little  resistance  to  the  sense  of  touch.  It  serves  chiefly 
as  a  covering  or  shield  for  the  under  parts,  to  prevent  irri- 
tation, corrosion,  and  the  absorption  of  pernicious  sub- 
stances into  the  circulation. 

The  Sudorific  and  Sebaceous  Glands. — The  skin 
is  furnished  with  numerous  small  glands  termed  secre- 
tory organs. 

The  sudorific  glands  secrete  sweat  or  perspirable  fluid 
from  the  circulation.     Their  function  is  of  great  import- 


THE  EXCRETORY  SYSTEM 


193 


ance,  and  serves,  in  the  first  place,  to  remove  the  excre- 
mental  or  exhausted  material  from  the  body;  and,  sec- 
ondly, to  regulate  the  temperature  by  means  of  evapo- 
ration of  the  fluid  thus  thrown  out.  For  example,  when 
the  body  has  been  exposed  to  heat  or  when  exercise  has 
been  indulged  in,  perspiration  is  abundant,  so  that  by  its 
evaporation  the  heat  may  be  dissipated. 


Fig.  98. — A  normal  sweat-gland,  highly  magnified :  a,  Sweat-coil,  with 
secreting  epithelial  cells ;  b,  sweat-duct ;  c,  lumen  of  duct ;  d,  connective- 
tissue  capsule  ;  e  and  /,  arterial  trunk  and  capillaries  supplying  the  gland 
(after  Neumann). 


These  little  sweat  or  sudorific  glands  have  a  spiral  out- 
let upon  the  surface,  but  their  entire  arrangement  is  so 
delicate  and  minute  that  they  cannot  be  viewed  by  the 
unaided  eye.  In  the  illustration  (Fig.  98)  the  parts 
showing  the  sudorific  glands  and  the  spiral  outlet,  passing 
through  the  different  layers  of  skin,  have  been  highly 
magnified. 

The  skin  is  also  furnished  with  other  glandular  organs, 

13 


194      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

the  sebaceous  glands   which  are  situated  in  the  armpits, 
and  in  the  face,  as  about  the  nose  and  ears.     These  fur- 


FlG.  99. — A  normal  sebaceous  gland  in  connection  with  a  lanugo  hair ; 
greatly  magnified  :  a.  Connective-tissue  capsule ;  b,  fatty  secretion  ;  c,  h, 
fat-secreting  cells  ;  d,  root  of  a  lanugo  hair ;  e,  hair-sac ;  /,  hair-shaft ;  g, 
acini  of  sebaceous  gland  (after  Neumann). 

nish  an  oily  secretion  to  the  skin  in  all  parts,  which  keeps 
it  soft  and  pliable. 


THE   APPENDAGES    OF   THE    SKIN 

The  appendages  of  the  skin  are  the  hair  and  nails. 

The  hair  is  a  peculiar  modification  of  the  epidermis,  and 
consists  essentially  of  the  same  structure  as  that  mem- 
brane.    It  consists  of  a  root,  a  shaft,  and  a  point.     The 


THE  EXCRETORY  SYSTEM 


195 


root  presents  a  bulbous  enlargement  at  its  extremity;  the 
shaft  consists  of  a  central  part  or  medulla. 

Hairs  are  found  on  almost  every  part  of  the  human 
body,  but  are  most  numerous  on  the  scalp,  and,  in  the 


it 
il'L 


Fig.  100. — Skin  and  longitudinal  section  of  hair :  a.  Epidermis ;  >, 
corium ;  c,  sebaceous  gland ;  d,  fibrous  root-sheath ;  e,  glassy  membrane ; 
/outer  root-sheath;  g,  inner  root-sheath;  h,  expanded  bulbous  end  of 
hair;  i,  papilla  of  hair;  j,  arrector  pili ;  k,  adipose  tissue  (Leroy). 


male,  on  the  face,  where,  in  the  beard,  they  are  thick  and 
coarse  in  character.  At  puberty  hair  appears  on  the  pubis 
and  in  the  armpits. 

The   nails  are  flattened,  elastic  structures  of  a  horny 
texture,  situated  upon  the  dorsal  surface  of  the  terminal 


196      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

phalanges  of  the  fingers  and  toes.  The  nail  has  a  firm 
attachment  to  the  cutis,  and  the  part  beneath  the  body 
and  root  is  called  the  matrix,  from  which  successive  growth 


Fig.  ioi.— Human  hair:  1,  The  hair  of  a  child;  2,  hair  of  an  adult;  3, 
pointed  extremity  of  the  hair  of  the  eyebrow  ;  a,  transverse  section  of  the 
hair,  showing  the  cortical  and  medullary  portions,  and  air-cells  in  the  center 
of  the  cylinder  (Chapman). 


of  the  nail  is  produced,  with  the  accumulation  of  the  cells 
therein. 

The  chemic  composition  of  the  nails  is  the  same  as  that 
of  the  epidermis,  with  a  larger  proportion  of  sulphur  and 
carbon. 

REVIEW    QUESTIONS 

What  do  you  understand  by  metabolism? 
What  is  known  by  elimination? 
What  are  the  waste  products.? 
What  constitutes  the  excretory  system? 
How  many  kidneys  are  there? 
What  is  the  function  of  the  kidneys? 
Give  the  location  of  the  kidneys. 
What  is  their  average  weight? 
What  are  the  Malpighian  bodies? 
Describe  the  structure  of  the  kidneys. 
Describe  the  uriniferous  tubules. 
Describe  the  ureters. 


THE  EXCRETORY  SYSTEM  1 97 

Describe  the  bladder. 

Describe  the  urethra. 

What  is  micturition? 

Describe  the  characteristics  of  normal  urine. 

What  is  the  specific  gravity?    Reaction? 

Upon  what  is  the  color  dependent? 

What  are  the  chief  constituents  of  urine? 

In  what  abnormal  conditions  do  we  find  albumin,  sugar,  pus,  uric 
acid? 

What  is  the  normal  amount  secreted  in  twenty-four  hours  for  an  adult 
in  health? 

How  may  the  specific  gravity  vary,  and  under  what  conditions? 

Describe  the  suprarenal  capsule. 

What  are  the  sudorific  glands?     What  is  their  function? 

Describe  sebaceous  glands. 

What  important  function  do  they  possess? 

How  does  the  skin  act  as  an  excretory  organ?  Upon  what  is  it  de- 
pendent? 

How  many  layers  are  there  in  the  skin? 

What  are  the  appendages  of  the  skin? 


CHAPTER    VII 

THE  NERVOUS  SYSTEM 

Th^  nervous  system  is  concerned  chiefly  with  the  func- 
tions of  sensation,  motion,  and  voHtion.  It  is  through  this 
system  that  all  actions,  voluntary  and  involuntary,  are 
controlled.  It  is  made  up  of  the  cerebrospinal  center,  and 
the  numerous  slender  or  thread-like  prolongations  that 
emanate  from  the  center,  called  nerves,  and  which  are 
distributed  to  every  tissue  and  part  of  the  body,  excepting 
the  extremities  of  the  nails,  the  hair,  and  adipose  tissue. 
The  substance  of  the  brain,  spinal  cord,  and  nerves  is  very 
similar.  It  is  of  soft  or  pulpy  consistence,  and  of  a  whit- 
ish or  cineritious  color. 

The  Brain. — The  brain  in  the  human  subject  is  large, 
and,  with  its  membranes  and  vessels,  occupies  the  cavity 
of  the  skull.  It  consists  of  three  portions — the  cerebrum, 
or  anterior  and  larger  portion,  the  cerebellum,  which  is 
about  one-seventh  the  size  of  the  cerebrum,  and  is  situ- 
ated in  the  back  and  lower  portion  of  the  skull,  and  the 
medulla  oblongata,  situated  below  the  cerebellum.  The 
brain  is  entirely  surrounded  by  membranes — the  dura 
mater,  the  arachnoid,  and  the  pia  mater. 

The  dura  mater  is  a  firm  membrane,  which  lines  the  cra- 
nial cavity  and  acting  as  the  periosteum  of  the  cranial 
bones.  It  forms  septa — the  falx  cerebri,  the  falx  cerebelli, 
and  the  tentorium — which  form  partitions  between  the 
different  parts  of  the  brain. 

The  arachnoid  is  a  serous  membrane  that  invests  the 
brain  and  spinal  cord.  lyike  other  serous  membranes,  it  is 
a  closed  sac. 

198 


THE   NERVOUS  SYSTEM  I99 

The  pia  mater  is  a  very  vascular  membrane.  It  in- 
vests nearly  the  entire  surface  of  the  brain,  and  dips  in 
between  its  convolutions.  It  is  the  nutrient  membrane  of 
the  brain,  and  receives  all  the  blood  from  the  carotid  and 
vertebral  arteries. 

The  Cerebrum. — The  cerebrum  is  divided  into  two 
hemispheres  by  a  cleft  or  fissure.  In  the  fissure  we  find 
a  circular  or  arched  projection  of  the  dura  mater,  called 
the  jalx  cerebri.  The  object  of  this  construction  is  to 
render  support  to  this  large  pulpy  mass.  The  upper 
surface  of  the  cerebrum  is  marked  by  many  undulations 
or  convolutions,  and  the  under  surface  admits  of  three 
divisions  in  each  hemisphere — the  anterior,  the  middle, 
and  the  posterior  divisions. 

When  the  brain  is  cut  through  its  upper  part  hori- 
zontally, and  the  part  removed  so  as  to  expose  the  cut 
surface,  it  will  be  discovered  that  the  substance  of  this 
organ  is  of  two  distinct  colors.  On  its  outer,  surf  ace  the 
brain,  for  a  small  depth,  is  of  an  ashen-gray  or  cineritious 
color,  while  the  central  portion  is  white.  This  darker 
portion  is  called  its  cortical  or  cineritious  portion;  in  its 
outlines  it  follows  the  convolutions  of  the  brain.  The 
light-colored  portion  is  called  the  .medullary  portion. 
The  two  hemispheres  of  the  cerebrum  are  connected  by  a 
dense  layer  of  transverse  fibers,  called  the  corpus  callosum. 

The  Cerebellum. — This  portion  of  the  brain  is  situated 
in  the  occipital  or  back  part  of  the  skull.  Like  the  sub- 
stance of  the  brain,  the  substance  of  this  portion  is  also  of 
two  colors.  When  the  cerebellum  is  cut  vertically,  the 
white  matter  has  a  beautiful  appearance,  resembling  the 
trunk  and  branches  of  a  tree,  and  known  as  the  ''arbor 
vitcB."  The  main  stem  of  this  structure  contains  a  col- 
lection of  gray  matter,  the  corpus  dentatum. 

The  Medulla  Oblongata. — By  referring  to  the  illustra- 
tion (Fig.  102)  you  will  see,  at  the  base  of  the  brain,  the 


200      ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

commencement  of  the  spinal  cord,  here  called  the  medulla 
oblongata.  It  is  an  elongated  structure,  consisting  of  three 
divisions  or  pairs  of  bodies,  called  the  corpus  pyramidale, 


Fig.  I02. — Base  of  brain  :  i.  2, 3,  Cerebrum  ;  4  and  5,  longitudinal  fissure  ; 
6,  fissure  of  Sylvius  ;  7,  anterior  perforated  spaces;  8,  infundibulum  ;  9, 
corpora  albicantia;  10,  posterior  perforated  space;  11,  crura  cerebri; 
12,  pons  Varolii;  13,  junction  of  spinal  cord  and  medulla  oblongata;  14, 
anterior  pyramid  ;  14^,  decussation  of  anterior  pyramid  ;  15,  olivary  body  ; 
16,  restiform  body ;  17,  cerebellum  ;  19,  crura  cerebelli ;  21,  olfactory  sulcus ; 
22,  olfactory  tract;  23,  olfactory  bulbs;  24,  optic  commissure;  25,  motor 
oculi  nerve ;  26,  patheticus  nerve ;  27,  trigeminus  nerve ;  28,  abducens 
nerve;  29,  facial  nerve;  30,  auditory  nerve;  31,  glosso-pharyngeal  nerve; 
32,  pneumogastric  nerve  ;  33,  spinal  accessory  nerve  ;  34,  hypoglossal  nerve. 


corpus  restiforme,  and  corpus  olivare,  united  in  a  single 
bulb.  The  medulla  oblongata,  unlike  the  brain,  is  highly 
sensitive,  and  if  even  slightly  punctured,  convulsions  ensue. 


THE  NERVOUS  SYSTEM 


20I 


Most  of  the  important  vital  centers  are  located  in  this 
portion  of  the  brain.  At  this  point  all  the  special  nerves 
diverge,  so  that  an  injury  to  this  part  produces  immediate 
disturbance  in  the  location  to  which  the  nerve  is  distrib- 
uted. 


Fig.  103.— View,  from  below,  of  the  connection  of  the  principal  nerves 
with  the  brain  :  I',  The  right  olfactory  tract;  II,  the  left  optic  nerve;  II', 
the  right  optic  tract  (the  left  tract  is  seen  passing  back  into  i  and  e,  the  in- 
ternal and  external  corpora  geniculata) ;  III,  the  left  oculomotor  nerve  ;  IV, 
the  trochlear;  V,  V,  the  large  roots  of  the  trifacial  nerves;  +  +,  the  lesser 
roots  (the  +  of  the  right  side  is  placed  on  the  Gasserian  ganglion) ;  i,  the 
ophthalmic ;  2,  the  superior  maxillary ;  and  3,  the  inferior  maxillary  divis- 
ions ;  VI,  the  left  abducens  nerve  ;  VII,  VIII,  the  facial  and  auditory  nerves  ; 
IX-XI,  the  glossopharyngeal,  pneumogastric,  and  spinal  accessory  nerves ; 
XII,  the  right  hypoglossal  nerve;  Ci,  the  left  suboccipital  or  first  cervical 
nerve  (Nancrede). 


The  Spinal  Cord. — The  spinal  cord  continues  from  the 
medulla  oblongata  downward  through  the  spaces  in  the 
vertebral  column  afforded  by  the  corresponding  openings 
of  the  vertebrae.     It  runs  throughout  the  entire  length  of 


202      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 


the  Spinal  canal,  extending  from  the  foramen  magnum  to 
the  lower  border  of  the  first  lumbar  vertebra,  where  it 
terminates  in  slender  filaments  of  gray  substance.  Its 
weight,  when  divested  of  all  its  membranes  and  nerves,  is 
about  \\  ounces.  It  is  usually  about  i6  or  17  inches  in 
length.     It  varies  in  its  diameter  at  different  locations. 


Fig.  104.— Different  views  of  a  portion  of  the  spinal  cord  from  the  cervi- 
cal region,  with  the  roots  of  the  nerves.  In  A  the  anterior  surface  of  the 
specimen  is  shown,  the  anterior  nerve-root  of  its  right  side  being  divided ; 
in  5  a  view  of  the  right  side  is  given  ;  in  C  the  upper  surface  is  shown ;  in 
D  the  nerve-roots  and  ganglion  are  shown  from  below:  i,  the  anterior 
median  fissure;  2,  posterior  median  fissure;  3,  anterior  lateral  depression, 
over  which  the  anterior  nerve-roots  are  seen  to  spread ;  4,  posterior  lateral 
groove,  into  which  the  posterior  roots  are  seen  to  sink;  5,  anterior  roots 
passing  the  ganglion ;  5',  in  A,  the  anterior  root  divided ;  6,  the  postenor 
roots,  the  fibers  of  which  pass  into  the  ganglion,  6;  7,  the  united  or  com- 
pound nerve ;  7',  the  posterior  primary  branch  seen  in  A  and  D  to  be  de- 
rived in  part  from  the  anterior  and  in  part  from  the  posterior  root  (Allen 
Thomson). 


It  is  grooved,  on  both  its  anterior  and  its  posterior  sur- 
face, by  a  furrow  that  divides  it  in  its  entire  length  into 
two  great  nervous  cords  intimately  united  with  each  other. 
These  lateral  cords  are  each  divided  by  furrows  into  three 
distinct  sets  of  fibers  or  columns;  namely,  the  anterior, 
lateral,  and  posterior  columns.  The  anterior  are  the 
motor  columns;   the  posterior,   those  of  sensation;   the 


THE  NERVOUS  SYSTEM  20 3 

lateral  columns  are  divided  in  their  function  between  mo- 
tion and  sensation. 

The  spinal  cord  terminates,  at  its  lower  extremity,  in 
an  oval  tubercle,  whence  arise  a  number  of  nerves  that 
go  tp  the  lower  parts  of  the  body.  From  the  appearance 
these  numerous  nerves  assume  as  they  emerge  from  the 
spinal  cord,  they  have  collectively  been  denominated,  the 
"cauda  equina,"  from  a  fancied  resemblance  to  a  horse's 
tail.  The  spinal  cord,  as  well  as  the  medulla  oblongata, 
is  enveloped  in  its  entire  length  by  the  continuation  of  the 
three  membranes  of  the  brain.  A  more  detailed  descrip- 
tion of  the  anatomic  structure  of  the  various  portions  of 
the  nervous  system  will  be  given  further  on. 

THE   NERVES 

The  nerves  are  tubular  cords,  the  substance  of  whose 
structure  is  similar  to  that  of  the  brain  and  spinal  cord. 
All  nerves  take  their  origin  in  the  brain  and  the  spinal 
cord,  and  extend  in  sets  to  every  part  of  the  body  by  differ- 
ent routes.  They  often  unite  in  their  course  and  form  a 
plexus.  There  are  43  pairs  of  primary  nerves  arising 
from  the  nervous  centers;  these,  according  to  their  origin, 
are  termed  cranial,  or  encephalic,  and  spinal  nerves. 
Twelve  pairs  originate  within  the  skull  and  31  pairs 
pass  from  the  spinal  cord — 8  cervical,  12  dorsal,  5  lum- 
bar, 5  sacral,  and  i  coccygeal. 

Each  nerve  is  composed  of  several  filaments  or  cords,  ly- 
ing alongside  one  another,  and  surrounded  by  the  neuri- 
lemma. Most  of  the  cranial  nerves  have  but  a  single  root, 
but  the  spinal  nerves  arise  by  two  roots — one  from  an 
anterior  fasciculus  of  filaments  and  the  other  from  a  pos- 
terior; these  are  separated  from  each  other  by  the  liga- 
mentum  denticulatum.  The  two  roots  later  join,  however, 
to  form  one  nerve. 

The  spinal  nerves,  as  has  just  been  stated,  arise  by 


204      ANATOMY  AND  PHYSIOLOGY  FOR   NURSES 

two  roots  from  the  anterior  and  posterior  columns  of 
the  spinal  cord.  The  posterior  roots  are  larger  than  the 
anterior.  The  anterior  are  the  motor  radicles,  and  the 
posterior,  the  sensory. 

On  each  of  the  posterior  roots,  in  the  openings  between 
the  bones  of  the  spinal  column  {intervertebral  foramina), 


^^ 


Fig.  105. — Longitudinal  nerve- 
fiber  (diagrammatic)  :  a.  Axis- 
cylinder  ;  b,  medullary  she  ith  ;  c, 
neurilemma ;  d,  nucleus ;  t,  node 
of  Ranvier  (Leroy). 


Fibrils  of  axial 

cord. 


—  -  Neurilemma. 


Segment  of 
Lantermann. 


Fig.  106,  —  Longitudinal  section 
through  a  nerve-fiber  from  the  sciatic 
nerve  of  a  frog  (x  830)  (Bohm  and 
Davidoff). 


a  ganglion  is  formed,  after  which  the  anterior  and  posterior 
roots  of  the  nerve  unite  and  form  the  spinal  nerve. 

The  ganglia  may  be  considered  as  distinct  centers, 
giving  off  branches  in  different  directions :  the  superior,  or 
ascending,  to  communicate  with  the  ganglion  above;  the 
inferior,  or  descending,  to  communicate  with  the  ganglion 
below;  the  external,  to  communicate  with  the  sympathetic 


THE   NERVOUS  SYSTEM 


205 


filaments.  It  is  generally  admitted  that  the  nerves  that 
emerge  from  the  ganglia  are  larger  than  those  that  enter 
them — as  if  the  ganglia  imparted  additional  power  to  the 


nerve. 


Fig 


.  107. — Transverse  section  of  a  nerve  :  a,  Epineurium  ;  b,  perineurium 
c,  endoneurium  ;  d,  section  of  a  single  fiber  (Leroy). 


The  branches  of  distribution  accompany  the  arteries 
that  supply  the  different  organs  and  form  communica- 
tions around  them ;  these  are  called  plexuses,  and  take  the 
name  of  the  artery  with  which  they  are  associated.     Thus 


Fig.  108. — Nerve-cell  with  dendrites  ending  in  claw-like  telodendria: 
a,  Neuraxis;  b,  telodendrion  (Bohm  and  Davidoff). 


we  have  the  mesenteric  plexus,  the  hepatic  plexus,  the 
splenic  plexus,  etc.  All  the  internal  organs  of  the  head, 
neck,  and  trunk  are  supplied  with  branches  from  the 
sympathetic  nerve,  and  some  of  them  exclusively.     This 


206      ANATOMY  AND  PHYSIOLOGY  FOR   NURSES 


nerve,  as  well  as  the  other  important  nerves  of^the  body, 

will  be  discussed  elsewhere. 

Functions  of  the  Nervous 
System.  —  The  cerebral  hemi- 
spheres are  the  centers  of  the 
nervous  system,  through  which 
are  manifested  all  the  phenom- 
ena of  the  mind;  they  are  the 
centers  in  which  impressions  are 
registered  and  subsequently  re- 
produced as  ideas;  they  are  the 
seat  of  intelHgence,  reason,  and 
will. 

However  important  a  center 
the  cerebrum  may  be  for  the  ex- 
hibition of  this  highest  form  of 
nervous  action,  it  is  not  directly 
essential  for  the  continuance  of 
life,  for  it  exerts  no  control 
over  those  automatic  reflex  acts, 
known  as  respiration,  circulation, 
etc.,  which  regulate  the  func- 
tions of  organic  life. 

The  brain  is  not  a  sensitive 
organ,  and  may  be  lacerated,  or 
portions  may  even  be  cut  away 
without  giving  rise  to  much 
pain ;  such  injuries,  however,  will 
immediately  affect  the  mental 
faculties.  The  cerebellum,  on  the 
other  hand,  is  in  close  relation 
with  the  functions  of  animal  life, 
and  any  interference  with  it  will 
immediately  affect  the  various 
functions  of  Hfe,  such  as  the  respiration,  the  digestion,  and 


Fig.  109. — General  view 
of  the  cerebrospinal  nervous 
system  (after  Bourgery ; 
Schwalbe). 


THE  NERVOUS  SYSTEM  20/ 

the  circulation.  The  medulla  oblongata  appears  to  be  the 
general  receptacle  of  the  impressions  of  the  nerves  of  the 
special  senses,  and  the  spinal  cord  that  of  general  sensa- 
tion. 

Functions  of  the  Nerves. — Of  the  spinal  nerves  and  of 
one  of  the  cranial  (trifacial),  it  may  be  stated  that  they 
have  two  roots — one  for  conveying  motor  and  one  for 
carrying  sensory  impulses.  In  other  words,  one  set  for 
the  functions  of  motion  and  the  other  for  those  of  sensa- 
tion. 

No  difference  has  been  discovered  in  the  structure  of 
the  several  kinds  of  nerves  in  any  part  of  their  course,  and 
the  functions  they  are  designed  to  perform  can  only  be 
learned  by  ascertaining  the  place  of  their  origin.  The 
nerves  may  be  divided  into  five  groups,  according  to  their 
functions : 

1.  Nerves  of  Special  Sensation. — ^There  are  the  first, 
second,  eighth,  and  ninth  pair  of  cranial  nerves,  and  are 
concerned  with  smelling,  seeing,  hearing,  and  tasting. 

2.  Nerves  of  General  Sensation. — In  those  parts  that 
require  sensation  for  safety  and  the  performance  of  their 
functions  there  is  an  abundant  supply  of  sensitive  nervous 
filaments.  The  nerves  of  sensation  are  distributed  chiefly 
to  the  skin.  Few  filaments  ramify  in  the  mucous  mem- 
branes and  muscles.  The  head  is  supplied  with  sensa- 
tion by  the  ophthalmic  and  superior  maxillary  divisions 
of  the  fifth  cranial  nerve;  the  remainder  of  the  body 
by  fibers  from  the  mixed  spinal  nerves. 

3.  Nerves  of  Motion. — To  these  belong  the  third,  the 
fourth,  part  of  the  fifth,  the  sixth,  the  seventh,  the  elev- 
enth, and  the  twelfth  pairs  of  cranial  nerves.  They  are 
distributed  to  the  muscular  fibers,  and,  by  their  action, 
give  rise  to  muscular  contraction.  (By  referring  to  the 
illustration.  Fig.  114,  the  several  nerves  that  control  the 
general  system  may  be  seen.) 


208      ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

4.  Mixed  Nerves. — These  contain  both  motor  and  sen- 
sory fibers.  They  are  the  inferior  maxillary  division  of  the 
fifth,  the  tenth  pair  of  cranial  nerves,  and  all  of  the  spinal 
nerves. 

5.  The  Sympathetic  Nerve. — The  sympathetic  nerve, 
also  called  the  trisplanchnic  nerve,  is  in  reality  a  system 
of  nervous  arrangement  adapted  particularly  for  the 
performance  of  the  functions  of  organic  life.  It  consists 
of  a  series  of  ganglia  united  by  intermediate  branches, 
and  distributes  its  regular  branches  in  the  three  great 
splanchnic  cavities — those  of  the  head,  chest,  and  abdo- 
men. In  the  trunk  it  lies  mainly  on  the  side  of  the  spine 
(the  student  should  carefully  study  the  illustration.  Fig. 
1 14,  in  order  to  become  familiar  with  this  important  nerve) 
and  communicates  with  all  the  spinal  and  several  of  the 
cranial  nerves. 

The  sympathetic  nerve  serves  to  maintain  vitality  in 
all  the  important  portions  of  the  system.  It  exerts  a 
controlling  influence  over  the  involuntary  functions  of 
digestion,  absorption,  secretion,  circulation,  and  nutrition. 
Every  portion  of  the  body  is,  to  a  certain  extent,  under  its 
influence,  as  filaments  from  this  system  of  nerves  accom- 
pany the  blood-vessels  throughout  their  course. 

An  important  function  of  the  sympathetic  system  is  to 
form  a  communication  of  one  part  of  the  system  with 
another,  so  that  when  one  organ  is  affected,  every  other 
organ  will  act  accordingly.  If,  for  example,  disease 
seizes  the  brain,  the  stomach,  by  its  sympathetic  connec- 
tion, becomes  aware  of  it;  and  since  nourishment  would 
augment  the  disease,  the  stomach  refuses  to  receive  food, 
and  perhaps  throws  off  what  has  already  been  taken.  The 
loss  of  appetite  in  certain  diseases  is  thus  a  kind  provision 
of  nature  that  prevents  our  taking  food  when  it  would  be 
injurious;  following  this  intimation,  we,  as  a  general  rule, 
should  abstain  from  food  until  the  appetite  returns. 


THE  NERVOUS  SYSTEM  209 

Having  described  briefly  the  several  portions  that  go 
to  make  up  the  nervous  system,  we  will  now  consider 
more  fully  the  anatomy  of  the  parts  connected  with  these 
important  structures. 

THE   BRAIN 

This  is  that  portion  of  the  cerebrospinal  center  con- 
tained in  the  cavity  of  the  cranium.  It  is  divided  into 
four  principal  parts :  the  medulla  oblongata,  pons  Varolii, 
cerebrum,  and  cerebellum. 

The  average  weight  of  the  brain  is  about  49  ounces  in 
the  male  and  44  ounces  in  the  female;  the  heaviest  male 
brain  of  which  there  is  a  record  weighed  68|  ounces;  the 
lightest,  34  ounces;  the  heaviest  female  brain  weighed  56 
ounces;  the  lightest,  30  ounces. 

The  brain  is  divided  into  fissures  and  lobes ;  the  fissures 
divide  the  several  parts  of  the  brain  substance,  and  in 
this  manner  the  several  lobes  are  marked  out. 

As  has  been  stated  elsewhere,  the  brain  is  surrounded 
by  three  membranes:  the  dura  mater,  which  is  a  tough, 
fibrous  membrane ;  the  arachnoid,  a  serous  membrane ;  and 
the  pia  mater,  a  vascular  membrane. 

The  Dura  Mater. — This  is  the  first  membrane  to  be 
encountered  after  the  removal  of  the  skull-cap.  It 
derived  its  name  from  the  fancied  belief  that  it  supplied 
all  the  membranes  of  the  body.  As  has  been  said,  it  is  a 
tough,  inelastic,  fibrous  structure,  forming  the  internal 
periosteum  of  the  skull.  It  acts  as  a  support  for  the 
lobes  of  the  brain,  and  forms  partitions  for  the  falx  cerebri, 
falx  cerebelli,  and  tentorium  cerebelli;  it  also  provides 
sinuses  for  the  veins  that  return  the  blood  from  the  brain ; 
further,  it  forms  sheaths  for  the  nerves  as  they  leave  the 
skull. 

The  Arachnoid  Membrane. — This  is  the  second  mem- 
brane, and  takes  its  name  from  its  resemblance  to  a  spider's 

14 


2IO      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

web.  It  is  a  very  delicate,  serous  membrane,  and,  like 
all  other  serous  membranes,  is  a  closed  sac — one  part,  form- 
ing the  parietal  layer,  lines  the  under  surface ;  the  other,  or 
visceral  layer,  is  reflected  over  the  brain. 

This  membrane  is  perfectly  smooth,  and  is  sufficiently 
lubricated  to  prevent  friction.  It  is  in  close  connection 
with  the  pia  mater.  At  the  base  of  the  brain  it  forms 
spaces,  known  as  subaracknoidean  spaces,  which  contain 
the  cerebrospinal  fluid;  this  fluid  serves  to  protect  the  brain 
and  nerve-centers  from  sudden  shocks  and  concussions, 
such  as  blows,  as  well  as  loud  noises.  The  base  of  the 
brain  is  supported  by  a  bed  of  water.  In  fractures  at  the 
base  of  the  skull  or  in  the  temporal  region  water  will  be 
seen  to  ooze  through  the  ear  and  along  the  line  of  the 
fracture;  this  symptom  is  generally  considered  as  proof 
of  the  presence  of  a  fracture. 

The  Pia  Mater.— This  is  the  third  membrane  that 
invests  the  entire  surface  of  the  brain,  and  forms  the 
velum  interpositum  and  choroid  plexuses  of  the  third  and 
fourth  ventricles.  It  is  extremely  vascular,  its  blood- 
supply  being  derived  from  the  internal  carotid  and  ver- 
tebral arteries,  and  forms  a  bed  in  which  the  blood-vessels 
divide  and  subdivide  before  they  enter  the  brain.  It 
dips  in  between  the  convolutions,  as  well  as  into  the  lateral 
ventricles,  to  supply  blood  to  the  interior  of  the  brain 
substance. 

The  great  mass  of  nervous  matter  termed  the  brain 
is,  as  we  have  said,  divided  into  three  great  parts — ^the 
cerebrum,  the  cerebellum,  and  the  medulla  oblongata. 

The  cerebrum  is  of  oval  form :  it  is  divided  in  the  middle 
Hne,  by  the  longitudinal  fissure,  into  two  parts,  termed  the 
right  and  the  left  hemisphere.  The  surface  of  the  hemi- 
spheres is  of  tortuous  character,  and  divided  by  furrows, 
or  sulci,  into  convolutions.  The  furrows  serve  to  accom- 
modate the  vessels  in  their  course  to  the  sinuses ;  they  also 


THE   NERVOUS  SYSTEM  211 

contain  fluid  from  the  subarachnoid  spaces.  In  old  age, 
or  in  cases  of  disease  in  which  the  convolutions  become 
shrunken,  large  quantities  of  water  are  present.  The 
convolutions  are  folds  of  the  brain  substance,  this  folding 
serving  to  give  greater  extent  to  the  circumference  of  the 
parts  and  also  a  greater  area  of  gray  matter.  This  is 
believed  to  be  the  location  of  the  mental  forces  and  of 
intelligence.  The  number  of  convolutions  and  their 
depth  vary  in  different  races. 

The  under  surface  of  the  brain  resembles  the  upper; 
it  presents  the  same  convoluted  appearance,  and  is  made 
up  of  three  lobes — the  anterior,  the  middle,  and  the  pos- 
terior.    (See  Fig.  102.) 

The  anterior  lobe  rests  on  the  roof  of  the  orbit,  and  is 
separated  from  the  middle  lobe  by  the  fissure  of  Sylvius, 
which  receives  the  lesser  wing  of  the  sphenoid  bone. 
It  contains  the  island  of  Reil.  The  middle  lobe  occupies 
the  middle  fossa  of  the  base  of  the  skull  formed  by  the 
sphenoid  and  temporal  bones.  The  posterior  lobe  rests 
upon  the  tentorium. 

We  will  now  examine  the  interior  of  th©  brain.  In 
separating  the  hemispheres  of  the  cerebrum  in  the  longi- 
tudinal fissure  we  find  what  is  termed  the  corpus  callosum. 
In  examining  the  brain  we  find  it  made  up  of  two  char- 
acteristic substances — the  white  and  the  gray  matter. 
The  gray  matter  is  about  |  inch  in  thickness,  and 
invests  the  brain  like  a  bark,  hence  it  is  termed  the 
cortical  substance.  The  furrows,  as  previously  stated, 
vary  in  number  and  in  depth,  according  to  the  intelligence 
of  the  individual.  To  the  naked  eye  the  cortical  substance 
appears  as  one  layer,  but  when  examined  under  the  mi- 
croscope six  layers  are  seen — three  gray,  alternating  with 
three  white.  The  central  white  tissue  is  called  the 
medullary  portion,  and  forms  the  mass  of  the  brain  sub- 
stance. 


2 1 2      ANA  TOMY  AND   PHYSIO  LOG  Y  FOR   NURSES 

The  corpus  callosum  is  the  transverse  portion  of  the 
brain  connecting  the  two  hemispheres ;  it  is  about  4  inches 
long.  It  is  composed  of  a  body,  a  genu,  and  a  splenium. 
It  roofs  in  the  lateral  ventricles  of  the  brain. 

There  are  five  ventricles  in  the  brain.  The  two  lateral 
are  covered  with  the  corpus  callosum,  and  are  formed  by 
the  folding  backward  of  the  cerebral  lobes.  They  contain 
a  quantity  of  a  serous  fluid,  which,  when  it  occurs  in  ex- 
cess, as  it  sometimes  does  in  children,  constitutes  the  dis- 
ease known  as  hydrocephalus.  It  has  an  anterior,  a 
middle,  and  a  posterior  horn. 

The  third  ventricle  lies  between  the  optic  thalami  and 
extends  to  the  base  of  the  brain. 

The  fourth  ventricle  is  situated  between  the  cerebellum 
and  the  posterior  parts  of  the  medulla  oblongata  and  pons 
Varolii. 

If  a  perpendicular  section  of  the  brain  were  made,  the 
lateral  ventricles,  as  well  as  the  third,  would  be  seen;  the 
corpus  callosum,  and  the  fornix  and  velum  interpositum 
below  it,  would  also  come  into  view. 

The  fornix  is  a  layer  of  white  matter,  arranged  in  the 
form  of  an  arch,  beneath  the  corpus  callosum. 

The  velum  interpositum  is  a  reflection  from  the  pia 
mater,  which  penetrates  the  ventricles  through  the  fissure 
beneath  the  posterior  border  of  the  corpus  callosum.  It 
is  a  vascular  veil,  and  is  rolled  up  in  form  of  a  fringe,  which 
is  called  the  choroid  plexus.  These  plexuses  are  made  up 
of  minute  arteries,  and  communicate  with  each  other 
through  the  foramen  of  Monro.  The  foramen  of  Monro 
is  not  really  a  foramen,  but  simply  a  communication 
between  the  third  and  the  two  lateral  ventricles.  The 
venae  Galeni,  two  in  number,  return  the  blood  through 
these  parts  and  ventricles  into  the  straight  sinus. 

The  optic  thalamus  is  an  elevation  upon  the  floor  of  the 
lateral  ventricles  immediately  behind  the  corpus  striatum. 


THE  NERVOUS  SYSTEM  213 

The  corpus  striatum  is  a  layer  of  white  and  gray  matter; 
the  under  part  corresponds  with  the  convolutions  at  the 
base  of  the  brain,  known  as  the  island  of  Rett. 

The  tubercula,  or  corpora  quadrigemina,  are  four  rounded 
eminences,  situated  two  on  each  side  behind  the  pineal 
gland;  they  consist  of  white  and  gray  matter;  the  gray 
matter  of  the  anterior  pair  giving  off  the  optic  nerve, 
which  pierces  the  ball  of  the  eye ;  hence  they  are  sometimes 
termed  the  optic  lobes. 

The  cerebellum  is  situated  in  the  occipital  fossa,  below 
the  posterior  lobes  of  the  cerebrum.  It  is  elliptic,  its 
broad  diameter  being  transverse.  Upon  transverse  sec- 
tion it  presents  an  appearance  resembling  the  branches  of 
a  tree;  hence,  as  has  been  stated  elsewhere,  it  has  been 
termed  the  arbor  vitce,  or  "tree  of  life."  It  is  considered 
to  be  more  complex  in  its  anatomic  arrangement  than  any 
other  part  of  the  body. 

The  pons  Varolii  is  situated  at  the  base  of  the  brain, 
just  above  the  medulla  oblongata,  and  rests  upon  the 
basilar  surface  of  the  occipital  bone.  It  has  a  diameter  of 
about  I  inch.  The  basilar  artery  runs  in  a  groove  upon 
its  inferior  surface. 

The  medulla  oblongata  is  that  part  of  the  central 
cerebrospinal  axis  that  connects  the  cerebrum  with  the 
spinal  cord,  it  is  also  connected  with  the  cerebellum  by 
the  restiform  bodies.  It  is  one  of  the  most  important 
divisions  of  the  nervous  system,  and  contains  the  nerve- 
centers  for  speech,  deglutition,  and  respiration.  Injury 
to  this  structure  is,  indeed,  fatal. 

The  medulla  oblongata  is  about  i\  inches  long,  and  lies 
above  the  basilar  groove  of  the  occipital  bone;  it  passes 
backward  through  the  foramen  magnum,  at  which  level 
the  spinal  cord  begins. 

It  is  divided  into  anterior  pyramids  which  are  continu- 
ous with  the  spinal  cord  on  the  anterior  of  the  same; 


214      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

they  are  pyramidal  in  form,  and  the  motor  fibers  of  each 
side  decussate  with  one  another.  This  is  apparent  from 
the  fact  that  in  conditions  in  which  one  side  of  the  brain 
is  affected,  loss  of  power  is  manifested  on  the  opposite 
side  of  the  body.  The  decussation  takes  place  only  be- 
tween' the  inner  fibers  of  the  pyramids,  and  also  from  the 
lateral  columns  of  the  cord. 

The  olivary  bodies  are  situated  on  the  outer  side  of  the 
pyramids.  The  restiform  bodies  are  on  the  outer  side 
of  and  behind  the  olivary  bodies.  They  diverge  from  each 
other  and  pass  into  the  cerebellum. 

The  Arterial  Supply  to  the  Brain. — As  was  stated 
in  a  previous  chapter,  the  circle  oj  Willis  is  formed  by 
the  two  internal  carotids  and  the  two  vertebral  arteries. 

The  internal  carotid  artery  enters  the  skull  through  a 
canal  in  the  petrous  portion  of  the  temporal  bone;  it 
becomes  very  tortuous,  and  passes  by  the  side  of  the 
sphenoid  bone,  giving  off  the  ophthalmic  artery.  It 
divides  into  the  anterior  and  middle  cerebral  arteries, 
which  supply  the  anterior  and  middle  cerebral  lobes  of  the 
brain.  (This  artery  has  been  more  fully  considered  in  the 
chapter  on  the  Circulatory  System.) 

The  anterior  cerebral  artery  distributes  branches  in  all 
directions.  It  runs  forward  upon  the  lower  surface  of  the 
brain,  and  then  curves  round  in  the  front  of  the  corpus 
callosum  to  pass  backward  along  the  dorsal  surface  of  this 
structure.  It  is  connected,  soon  after  its  origin,  with  the 
artery  of  the  opposite  side  by  a  communicating  branch. 
The  middle  cerebral  artery  runs  outward  along  the  fissure  of 
Sylvius,  distributing  large  branches  to  the  anterior  and 
middle  lobes  of  the  brain. 

The  vertebral  artery,  after  winding  backward  along  the 
arch  of  the  atlas,  enters  the  skull  through  the  foramen 
magnum,  and  unites  with  its  fellow  at  the  lower  border  of 
the  pons,  to  form  the  basilar  artery;  it  then  divides  at  the 


THE   NERVOUS  SYSTEM  215 

middle  of  the  pons  into  the  two  posterior  cerebral  arteries, 
which  supply  the  posterior  cerebral  lobes.  At  the  pons 
the  basilar  gives  off  the  auditory  artery,  which  enters  the 
internal  auditory  meatus  together  with  the  auditory  nerve. 
It  also  gives  off  the  superior  and  inferior  cerebellar  arteries 
for  the  supply  of  the  upper  and  lower  surface  of  the  cere- 
bellum, and  eventually  enters  the  circle  of  Willis. 

The  circle  of  Willis  provides  a  free  supply  of  blood  from 
the  several  arteries  of  which  it  is  formed — the  anterior 
communicating  in  front;  the  two  posterior  communicating 
behind;  the  former  running  between  the  two  anterior 
cerebral  arteries,  the  latter  from  the  posterior  cerebral  to 
the  carotid.  The  tortuosity  of  the  vessels  before  entering 
the  brain  provides  a  means  to  divert  the  excessive  force 
of  the  blood  in  the  small  vessels ;  the  four  vessels  that  enter 
the  skull  break  up  and  form  minute  branches,  and  it  is 
for  this  reason  that  congestion  of  the  brain  is  relieved  only 
with  difficulty  and  recovery  therefrom  is  slow. 

In  considering  the  cerebral  circulation,  mention  must 
be  made  of  the  important  part  played  by  the  meningeal 
arteries. 

The  meningeal  arteries  ramify  between  the  dura  mater 
and  the  skull.  Their  most  important  branch  is  the 
middle  meningeal,  a  branch  of  the  internal  maxillary  artery, 
which  enters  the  skull  through  the  foramen  spinosum, 
passes  through  a  groove  in  the  sphenoid  bone  and  anterior 
angle  of  the  parietal  bones  to  the  top  of  the  skull,  giving 
off  branches  in  every  direction.  The  arteries  are  accom- 
panied by  corresponding  veins.  The  other  branches  are  of 
less  importance — the  anterior  is  given  off  from  the  internal 
carotid  within  the  cranial  cavity;  the  posterior  is  a  branch 
of  the  occipital,  and  enters  the  skull  through  the  jugular 
foramen. 

The  sinuses  of  the  brain  are  venous  channels; 
they  run  in  pairs  and  as  single  sinuses ;  there  are  five  pairs 


2l6      ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

and  five  single  sinuses.  It  is  a  peculiarity  of  the  cerebral 
circulation  that  the  venous  blood  is  returned  through  these 
canals  or  sinuses. 

The  cerebral  sinuses  are  formed  by  a  separation  of  the 
dura  mater  into  layers  and  are  unyielding  structures. 
They  are  lined  by  the  same  smooth  membrane  that  lines 
the  veins. 

As  has  been  said,  there  are  fifteen  sinuses;  their  names 
are  given  below,  and  their  arrangement  should  be  studied. 

Lateral  (2).  Circular. 

Superior  petrosal  (2).  Superior  longitudinal. 

Inferior  petrosal  (2).  Inferior  longitudinal. 

Cavernous  (2).  Transverse. 

Occipital  (2).  Straight. 

All  these  eventually  discharge  their  blood  into  the  in- 
ternal jugular  veins. 

The  spinal  system  of  veins  is  considered  together  with 
the  sinuses,  as  there  is  an  extensive  communication  of 
vessels  along  the  spinal  column,  their  structure  resembling 
that  of  a  ladder;  these  all  discharge  through  the  inter- 
vertebral foramina  into  the  several  regions  of  the  spine 
as  follows :  In  the  cervical  region,  into  the  vertebral  veins ; 
in  the  dorsal  region,  into  the  intercostal  veins;  in  the 
lumbar  region,  into  the  lumbar  veins.  These  veins  are 
not  provided  with  valves,  which  accounts  for  the  serious 
conditions  that  result  from  injuries  and  inflammation  of 
the  spine. 

THE   SPINAL   CORD 

The  spinal  cord  does  not  occupy  the  whole  area  of  the 
spinal  canal;  the  space  is  filled  up  with  a  reddish,  fatty 
substance,  and  with  the  associated  ramification  of  veins. 

The  Membranes  of  the  Cord. — The  dura  mater  does 
not  adhere  to  the  vertebra,  therefore  it  is  not  called  the 
internal  periosteum,  as  in  the  skull;  if  this  were  the  case, 


THE  NERVOUS  SYSTEM 


217 


the  adhesions  would  interfere  with  the  movements  of  the 
vertebra  upon  each  other.  The  dura  mater  sends  off 
branches  over  each  of  the  spinal  nerves.  The  arachnoid 
membrane  is  continuous  with  that  of  the  brain.  Its  spaces 
contain  a  watery  fluid  in  which  the  cord  may  float. 

The  pia  mater  immediately  invests  the  cord,  and 
serves  to  support  it;  it  plays  a  different  role  here,  there- 
fore, than  it  does  in  the  brain.     It  is  less  vascular  and 


a-gb.  /, 


Fig.  no. — ^Spinal  cord,  cervical  region  (diagrammatic),  showing  secondary 
tracts  of  white  matter,  the  dark  area  representing  descending  fibers,  dotted 
area  ascending  fibers,  cross-lined  area  mixed  fibers,  and  clear  area  gray  mat- 
ter: /./.,  Direct  pyramidal  tract ;  «.^.^.,  anterior  ground-bundle  ;  rf.t.,  direct 
cerebellar  tract ;  a.a.l.,  ascending  anterolateral  or  Gowers"  tract ;  c.p.,  crossed 
pyramidal  tract;  ^.a./.,  descending  anterolateral  tract;  w./.,  mixed  lateral 
tract;  g,  column  of  Goll;  b,  column  of  Burdach  (Leroy). 


more  fibrous  in  structure  than  the  pia  mater  of  the  brain. 
It  is  closely  adherent  to  the  cord,  forming  what  is  called 
the  neurilemma.  The  pia  mater  sends  off  ligaments  from 
each  side  to  steady  the  spinal  cord;  these  are  called  the 
ligamenta  dentata;  they  are  eighteen  to  twenty  in  number 
on  each  side,  and  lie  between  the  anterior  and  posterior 
roots  of  the  spinal  nerves. 

The  Spinal  cord  is  that  part  of  the  cerebrospinal  axis 
contained  in  the  vertebral  canal.     It  is  a  continuation  of 


21 8      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

the  medulla  oblongata,  and  runs  to  the  upper  border  of  the 
first  or  the  second  lumbar  vertebra,  where  it  divides  into 
a  bundle  of  nerves,  called  the  cauda  equina,  which  supply 
the  lower  limbs. 

The  cord  is  cylindric  in  form,  and  slightly  flattened 
from  before  backward.  On  its  anterior  and  posterior 
surfaces  it  presents  fissures;  laterally  it  is  provided  with 
two  grooves  on  each  side,  from  which  the  spinal  nerves 


0    n     a    J 


Fig.  III. — Lurtibar  section  of  spinal  cord,  showing  main  tracts  of  white 
substance  and  location  of  principal  groups  of  nerve  cells  in  gray  matter  :-rtf, 
Anterior  median  fissure  ;  b,  posterior  median  fissure ;  c,  anterior  horn  of 
gray  matter  ;  d,  posterior  horn  of  gray  matter  ;  e,  central  canal ;  f,  anterior 
white  commissure  ;  £■,  posterior  white  commissure ;  h,  i,  anterior  and  pos- 
terior gray  commissures  ;  j\  anterior  median  column  ;  K,  lateral  column  ; 
L,  posterior  column  ;  m,  column  of  Clarke;  n,  inner  group  of  nerve  cells; 
0,  anterior  group  ;  /,  anterolateral  group  ;  q,  posterolateral  group  ;  r,  lateral 
horn  (Leroy). 


emerge.  It  is  divided  into  three  columns — anterior,  pos- 
terior, and  lateral;  the  fibers  of  the  anterior  are  motor,  the 
posterior  sensitive,  while  those  of  the  lateral  are  of  both 
varieties. 

In  making  a  transverse  section  of  the  cord  it  will  be 
observed  (see  Fig.  iii)  that  the  interior  contains  gray 
matter,  which  resembles  two  crescents  placed  one  in  each 
half,  and  connected  across  the  center  by  a  band  called  the 


THE  NERVOUS  SYSTEM  2I9 

gray  commissure.  Each  crescentic  mass  has  an  anterior 
and  a  posterior  horn.  The  posterior  horns  are  long  and 
narrow,  and  are  connected  with  the  posterior  roots  of  the 
spinal  nerves.  The  anterior  horns  are  shorter  and  thicker, 
and  are  directed  forward  toward  the  anterior  roots  of  the 
nerves,  but  do  not  reach  the  surface. 

The  Spinal  nerves  will  be  subsequently  considered. 

THE   NERVES    OF    THE    GENERAL    SYSTEM 

We  will  now  discuss  the  several  nerves  that  control  the 
general  system.  Of  these,  the  first  to  be  considered  are 
the  cranial. 

The  Cranial  Nerves.— The  first,  or  olfactory,  is  the 
nerve  of  smell.  It  arises  from  the  olfactory  bulb  and 
terminates  in  the  olfactory  tract,  which  has  three  roots — 
inner,  middle,  and  outer.  The  olfactory  nerves,  coming 
from  the  olfactory  bulb,  are  divisible  into  three  groups: 
the  inner  supplies  the  mucous  membrane  of  the  septum 
of  the  nose;  the  middle  supplies  the  roof  of  the  nose;  the 
outer  supplies  the  turbinated  bones.  The  common  sensi- 
bility of  the  mucous  membrane  of  the  nose  is  derived  from 
the  fifth  nerve. 

The  second,  or  optic,  nerve  is  the  nerve  of  sight.  It 
arises  from  the  anterior  pair  of  the  corpora  quadrigemina 
and  optic  thalami.  It  rests  on  the  sphenoid  bone,  then 
passes  through  the  optic  foramen  to  terminate  in  the 
retina.  This  nerve  decussates  at  the  middle  of  the  com- 
missure, a  fact  for  which  there  seems  to  be  no  definite 
reason. 

The  third  pair,  or  the  motor  oculi,  apparently  arises 
from  the  inner  surface  of  the  crus  cerebri,  immediately  in 
front  of  the  pons;  it  passes  through  the  sphenoid  fissure 
and  supplies  all  the  muscles  of  the  eye,  except  the  superior 
oblique  and  the  external  rectus. 

The  fourth  nerve,  or  pathetic,  arises  from  the  valve  of 


220      ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

Vieussens,  enters  the  orbit  through  the  sphenoid  fissure, 
and  suppHes  the  superior  obHque  muscle  of  the  eye. 


Fig.  112. — Superficial  branches  of  cervical  plexus  :  i,  Superficial  cer- 
vical nerve ;  2,  its  inferior  branch  ;  3,  its  superior  branch  ;  4,  its  union  with 
facial;  5,  great  auricular  nerve;  6,  one  of  its  facial  branches;  7,  its  branch 
to  lobule;  8,  twig  which  pierces  the  auricle;  9,  branch  to  deep  surface  of 
pinna;  10,  its  union  with  posterior  auricular  of  the  facial;  11,  small  occipi- 
tal nerve ;  12,  its  branches ;  13,  a  mastoid  branch  ;  14,  twigs  from  this  to 
back  of  neck  ;  15,  inner;  16,  17,  middle;  18,  outer  branches  of  supraclavic- 
ular nerves;  19,  branch  of  cervical  nerves  passing  into  trapezius  muscle; 
20,  spinal  accessory  distributed  to  same,  and  receiving  a  uniting  branch  from 
the  cervical  nerves;  21,  branch  to  levator  scapulae;  22,  trunk  of  the  facial 
nerve ;  23,  its  posterior  auricular  branch ;  24,  its  cervical  branch ;  25,  great 
occipital  nerve. 


The  fifth  nerve,  called  the  trifacial,  is  the  great  sensory- 
nerve  of  the  head  and  face  and  the  motor  nerve  of  the 
muscles  of  mastication.     It  is  a  nerve  of  general  sensation 


THE   NERVOUS  SYSTEM  221 

and  motion,  and  arises  by  two  roots  from  the  floor  of  the 
fourth  ventricle  of  the  brain.  The  sensory  root  has  de- 
veloped upon  it  one  of  the  most  important  ganglia  of  the 
head — the  Gasserian.  This  nerve  gives  off  three  branches 
— the  ophthalmic  division  of  the  fifth,  the  superior  max- 
illary, and  the  inferior  maxillary.     (See  Fig.  112.) 

The  ophthalmic  division  again  divides,  giving  off  the 
frontal,  the  lacrimal,  and  the  nasal  branches.  The 
ophthalmic  is  a  sensory  nerve,  and  supplies  the  eyeball, 
ciliary  muscles,  iris,  lacrimal  gland,  nasal  and  ocular 
mucous  membrane,  skin,  and  the  muscles  of  the  eyebrow, 
forehead,  and  nose. 

The  superior  maxillary  is  also  a  sensory  nerve,  and  is 
distributed  to  the  temple,  cheek,  lower  eyelid,  nose,  upper 
lip,  teeth,  the  palate,  and  the  pharynx.  This  branch 
divides  again  into  the  several  nerves  that  supply  the  va- 
rious parts,  as  follows :  Superior  dental,  infra-orbital,  men- 
ingeal, two  sphenopalatine,  and  orbital.  The  superior 
dental  divides  into  the  anterior,  middle,  and  posterior 
dental.  The  infra-orbital  divides  into  the  palpebral,  nasal, 
and  labial. 

The  inferior  maxillary  division  of  the  fifth  nerve  is 
subdivided  into  the  meningeal,  masseteric,  three  temporal, 
buccal,  two  pterygoids,  lingual,  auriculotemporal,  and 
inferior  dental,  which  last  subdivides  into  the  dental,  my- 
lohyoid, incisive,  and  mental.  The  inferior  maxillary 
is  a  nerve  of  common  sensation  and  motion.  It  supplies 
the  muscles  of  mastication,  gums,  temples,  external  ear, 
teeth,  lower  lip,  tongue,  maxillary  ganglia,  and  lower  part 
of  the  face. 

The  sixth  nerve,  or  the  abducens,  arises  from  the  me- 
dulla oblongata  close  to  the  pons,  passes  through  the 
sphenoid  fissure,  and  supplies  the  external  rectus  of  the 
eye. 

The  seventh  nerve,  or  facial  nerve,  arises  as  two  por- 


222      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

tions.  It  is  the  motor  nerve  of  the  muscles  of  the  face. 
It  takes  its  origin  in  the  pons  VaroHi  and  lateral  columns 
of  the  medulla,  and  has  its  deep  origin  in  the  floor  of  the 
fourth  ventricle.  Its  branches  are  the  tympanic,  chorda 
tympani,  posterior  auricular,  digastric,  stylohyoid,  tem- 
porofacial  (which  subdivides  into  temporal,  malar,  infra- 
orbital), cervicofacial  (which  subdivides  into  buccal,  su- 
pramaxillary,  and  inf ramaxillary ) .  The  facial  communi- 
cates with  the  auditory  nerve;  with  Meckel's  ganglion  by 
the  large  petrosal;  with  the  optic  ganglion  by  the  small 
petrosal;  with  the  sympathetic  on  the  middle  meningeal 
by  the  external  petrosal  nerve;  with  the  pneumogastric, 
glossopharyngeal,  carotid  plexus,  auricularis  magnus,  au- 
riculotemporal, and  with  the  three  divisions  of  the  fifth 
nerve.  The  importance  of  this  nerve  is  apparent  from  its 
many  communications,  and  it  can  readily  be  seen  that  in- 
jury to  a  part  will  interfere  with  the  several  relations  of  this 
nerve  structure. 

The  eighth,  or  auditory,  is  the  nerve  of  hearing.  It 
begins  by  two  roots,  arising  from  the  medulla  oblongata; 
it  is  distributed  to  the  internal  ear  by  two  branches — the 
vestibular,  to  the  vestibule,  and  the  cochlear,  to  the  cochlea. 

The  ninth,  or  glossopharyngeal,  is  a  nerve  of  common 
sensation,  and  also  the  nerve  for  the  special  sense  of  taste. 
It  arises  from  the  medulla  oblongata,  behind  the  olivary 
bodies,  the  deeper  origin  being  from  the  floor  of  the  fourth 
ventricle.  This  nerve  emerges  through  the  jugular  fora- 
men, and  presents  two  enlargements  or  ganglia — the 
jugular  and  the  petrosal.  It  is  distributed  to  the  muscles 
of  the  pharynx,  mucous  membranes  of  the  pharynx,  fauces, 
tonsils,  tongue,  and  middle  ear;  for  that  purpose  it  gives 
off  the  following  branches,  which  are  distributed  to  the 
various  parts  indicated  by  their  names:  Tympanic,  caro- 
tid, pharyngeal,  muscular,  tonsillar,  and  lingual. 

The  tenth,  the  pneumogastric,  called  the  vagus  nerve, 


THE  NERVOUS  SYSTEM 


223 


has  many  points  of  interest;  it  gives  off  a  great  many- 
nerves  to  important  structures,  and  is  both  motor  and 


Fig.  113. — Distribution  and  connection  of  pneumos^astric  nerve  of  left 
side  in  neck  and  upper  part  of  thorax:  i,  Pneumognstric  nerve;  2,  gan- 
glion of  its  trunl<  ;  3,  accessory  part  of  spinal  accessory  ;  4,  union  o£  pneumo- 
gastric  with  hypoglossal;  5,  pharyngeal  branch  of  pneumogastric ;  6,  supe- 
rior laryngeal;  7,  external  laryngeal ;  8,  communication  of  external  laryn- 
geal with  superior  cardiac  branch  of  sympathetic  ;  9,  inferior  or  recurrent 
laryngeal;  10,  superior,  and  11,  inferior,  cervical  cardiic  branches;  12,  13, 
posterior  pulmonary  plexus;  14,  lingual  branch  of  inferior  niaxillary;  15, 
distal  part  of  hypoglossal  nerve ;  16,  glossopharyngeal  nerve  ;  17,  spinal 
accessorv  nerve  ;  18,  second  cervical  nerve  ;  19,  third  ;  20,  fourth  ;  21,  origin 
of  phrenic  nerve;  22,23,  fifth,  sixth,  seventh,  and  eighth  cervical  nerves, 
forming  with  the  first  dorsal  the  brachial  plexus;  24,  superior  cervical  gan- 
glion of  sympathetic  ;  25,  middle  cervical  ganglion  ;  26,  inferior  cervical  gan 
glion;  27,  28,  29,  30,  second,  third,  fourth   and  fifth  dorsal  ganglia. 


sensory.     It  arises  from  the  floor  of  the  fourth  ventricle, 
passes  through  the  jugular  foramen,  and  presents  two  gan- 


224      ANATOMY  AND  PHYSIOLOGY  FOR   NUJ^SES 

glia.  It  is  distributed  to  the  vocal  cords,  lungs,  pharynx, 
esophagus,  stomach,  and  heart.  It  gives  off  the  following 
branches:  Meningeal,  auricular,  pharyngeal,  superior 
laryngeal,  recurrent  laryngeal,  cervical  cardiac,  thoracic 
cardiac,  anterior  pulmonary,  posterior  pulmonary,  esoph- 
ageal, gastric,  and  abdominal  plexuses.     (See  Fig.  113.) 

The  eleventh,  or  spinal  accessory,  is  a  motor  nerve, 
having  its  origin  in  the  medulla  oblongata,  and  making 
its  exit  through  the  foramen  magnum;  it  is  distributed 
to  the  muscles  of  the  neck,  pharynx,  and  palate,  and  is 
said  to  be  a  constrictor  nerve  of  the  heart. 

The  twelfth,  or  h3rpoglossal,  is  a  motor  nerve  that  sup- 
plies the  tongue.  It  arises  from  the  floor  of  the  fourth 
ventricle,  and  makes  its  exit  through  the  anterior  condy- 
loid foramen.  It  gives  off  the  meningeal,  muscular,  and 
vascular  branches.  It  supplies  the  tongue  and  the  in- 
ternal muscles  of  the  throat,  and  communicates  with  the 
second  and  third  cervical  and  sympathetic  nerves. 

The  Spinal  nerves  arise  from  the  spinal  cord.  There 
are  31  pairs  of  these  nerves — 8  cervical,  12  dorsal,  5  lum- 
bar, 5  sacral,  i  coccygeal.  The  function  of  these  nerves 
has  already  been  described.  The  following  notes  are 
taken  from  the  researches  of  Blandin.^  He  says,  regarding 
the  relative  size  of  the  anterior  and  posterior  roots  of  the 
several  regions  of  the  spine: 

The  posterior  roots  are  to  the  anterior  in  the  cervical  region  .  .  .  .2:1 
The  posterior  roots  are  to  the  anterior  in  the  dorsal  region  .  .  .  .  i  :  i 
The  posterior  roots  are  to  the  anterior  in  the  lumbar  and 

sacral  regions 1^:1 

This  writer  states  further  that  this  relation  quite  accords 
with  the  great  delicacy  of  the  sense  of  touch  in  the  upper 
extremities. 

Each  spinal  nerve,  as  has  been  stated,  arises  by  two 
^Anat.  descript.,  1838,  t.  ii.,  p.  648. 


THE  NERVOUS  SYSTEM  225 

roots — an  anterior  or  motor  root,  and  a  posterior  or  sensory 
root.  We  will  now  consider  the  several  spinal  nerves 
individually. 

The  brachial  plexus,  sometimes  called  the  axillary,  is 
made  up  of  the  anterior  divisions  of  the  four  lower  cervical 
and  first  dorsal  nerves. 

The  nerves  forming  the  plexus  communicate  as  follows : 
The  fifth  and  sixth  nerves  unite  near  their  exit  from  the 
spine  to  form  a  common  trunk;  the  seventh  nerve  joins 
this  trunk  near  the  outer  border  of  the  middle  scalenus 
muscle,  and  the  three  nerves  thus  form  one  large  single 
cord.  The  eighth  cervical  and  the  first  dorsal  nerves  form 
a  common  trunk.  Thus  two  large  trunks  are  formed,  the 
upper  one  by  the  union  of  the  fifth,  sixth,  and  seventh 
cervicals;  and  the  lower  by  the  eighth  cervical  and  the 
first  dorsal.  These  two  trunks  accompany  the  subclavian 
artery  to  the  axilla,  lying  upon  the  outer  side,  the  trunk 
formed  by  the  union  of  the  last  cervical  and  the  first  dorsal 
being  nearest  the  vessel.  Opposite  the  clavicle,  and  some- 
times in  the  axilla,  each  of  these  cords  gives  off  a  fascicu- 
lus, which,  uniting,  form  a  third  trunk,  so  that  in  the  center 
of  the  axilla  three  cords  are  formed.  The  brachial  plexus 
communicates  with  the  cervical  plexus  by  a  branch  from 
the  fourth  to  the  fifth  nerve,  and  with  the  phrenic  by  a 
branch  from  the  fifth  cervical,  which  joins  that  nerve  on 
the  scalenus  muscle.  It  is  through  this  latter  addition 
that  in  cardiac  pains  the  sensation  is  felt  in  the  elbow. 
The  three  cords  of  the  brachial  plexus  are  placed  one  on  the 
inner  side  of  the  axillary  artery,  one  behind,  and  the  third 
on  the  outer  side. 

The  plexus  is  broad,  becoming  narrower  as  it  passes 
down  the  arm,  but  at  the  axilla,  where  it  divides  into 
terminal  branches,  it  is  larger.  This  plexus  communi- 
cates with  the  cervical  plexus  by  a  branch  from  the  fourth 
nerve,  and  also  receives  branches  from  the  two  inferior 

15 


226      ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

cervical  ganglia  of  the  sympathetic.  At  the  neck  it  gives 
off  the  following  branches,  which  are  distributed  to  the 
several  regions  that  each  name  designates. 

Thoracic  region.  Scapular  region. 

Anterior  thoracic.  Superior  muscular. 

Posterior  thoracic.  Suprascapular. 

Subscapular. 

Brachial  region. 
Musculocutaneous.  Ulnar. 

Median.  Lesser  internal  cutaneous. 

Internal  cutaneous.  Musculospiral. 

Circumflex. 

The  Dorsal  Nerves. — These  are  twelve  in  number,  and 
correspond  to  the  dorsal  vertebrae;  they  supply  the  several 
muscles  of  the  chest  and  side. 

The  intercostals  are  formed  from  the  dorsal  and  supply 
the  intercostal  spaces,  pleura,  mammary  vessels,  the 
muscles  of  the  chest  and  side  of  the  throat;  the  six  lower 
supply  the  internal  oblique  and  transversalis  muscles,  and 
continue  to  the  sheath  of  the  rectus;  after  supplying  this 
muscle  they  go  on  to  the  linea  alba,  and,  diverging,  form 
the  anterior  cutaneous  nerves  of  the  abdomen. 

The  lumbar  nerves  are  five  in  number  on  each  side. 
The  anterior  branches  of  the  four  upper  nerves  anasto- 
mose to  form  the  lumbar  plexus.  The  plexus  sends  off 
the  following  branches : 

The  Iliohypogastric  Branch. — This  proceeds  from  the 
first  lumbar  nerve,  and  supplies  the  muscles  of  the  hip 
and  abdomen;  it  is  distributed  to  the  iliac  region  from 
the  iliac  branch;  to  the  internal  abdominal  ring  from  the 
hypogastric  branch. 

The  ilio-inguinal  nerve  arises  from  the  first  lumbar,  and 
supplies  the  external  abdominal  ring,  the  pudenda,  sper- 


THE  NERVOUS  SYSTEM  22/ 

matic  cord,  scrotum,  and  the  integument  of  the  upper 
thigh. 

The  genitocrural  nerve  arises  from  the  second  lumbar, 
enters  the  muscles  of  the  anterior  part  of  the  thigh,  and 
descends  to  near  Poupart's  ligament,  where  it  divides  into 
the  genital  and  crural  branches.  The  genital  gives  off 
branches  to  the  internal  abdominal  ring  and  to  the  genital 
organs  of  the  female;  at  the  internal  abdominal  ring  it 
sends  off  branches  to  the  internal  oblique  and  transversalis 
muscles,  and  is  lost  in  the  integument  of  the  groin.  The 
crural  branch,  the  most  external,  descends  along  the  outer 
border  of  the  external  iliac  artery,  and  enters  the  sheath 
of  the  femoral  artery ;  it  is  distributed  to  the  upper  as  well 
as  the  anterior  aspect  of  the  thigh,  communicating  with 
the  middle  cutaneous  nerve. 

The  external  cutaneous  nerve  arises  from  the  second 
lumbar  nerve,  or  from  a  loop  between  it  and  the  third;  it 
passes  into  the  thigh,  beneath  Poupart's  ligament,  where 
it  divides  into  two  branches — the  posterior  and  the  an- 
terior, the  posterior  furnishing  branches  to  the  tensor 
vaginae  f emoris  muscle  and  posterior  part  of  the  thigh ;  the 
anterior  divides  into  several  branches,  which  are  distrib- 
uted to  the  outer  border  of  the  thigh  and  knee. 

The  obturator  is  formed  from  the  third  and  fourth  lum- 
bar nerves.  It  makes  a  distribution  to  the  obturator 
muscles,  femoral  and  popliteal  arteries,  knee-joint,  hip, 
and  integuments  of  the  upper  and  inner  part  of  the  thigh. 
At  its  origin  it  courses  along  the  common  iliac  until  it 
reaches  the  pelvic  brim,  where  it  passes  through  the 
obturator  foramen  and  joins,  in  its  course,  the  obturator 
artery;  having  escaped  from  the  pelvis,  it  divides  into 
anterior,  posterior,  and  accessory  branches,  which  supply 
the  several  muscular  structures  of  the  lower  extremity. 

The  anterior  crural  nerve,  sometimes  called  the  femoral 
nerve,  is  the  largest  branch  of   the  lumbar  plexus;  it  is 


228      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

formed  by  the  union  of  the  second,  third,  and  fourth  lum- 
bar nerves.  It  is  distributed  to  the  several  muscles  of  the 
thigh;  at  Poupart's  ligament  it  separates,  and  is  divided 
into  an  anterior  and  a  posterior  part,  which  give  off  the 
following  branches,  which  supply  the  structures  their 
names  imply.  Anterior  division:  Middle  cutaneous,  in- 
ternal cutaneous,  long  saphenous.  Posterior  division: 
Muscular  and  articular. 

The  sacral  nerves  are  five  in  number  on  each  side; 
they  pass  through  the  sacral  foramina,  the  last  one 
running  between  the  coccyx  and  sacrum ;  their  function  is 
to  supply  the  several  pelvic  organs.  The  coccygeal 
nerve  supplies  the  coccygeus  muscle  and  unites  with  the 
fifth  sacral. 

All  the  anterior  cords  of  the  sacral  nerves  communicate 
with  the  sympathetic  at  the  points  where  they  leave  the 
sacral  canal. 

The  sacral  plexus  of  nerves  is  composed  of  the 
lumbosacral  and  the  anterior  branches  of  the  three  upper 
and  part  of  that  of  the  fourth  sacral  nerves ;  it  gives  off  the 
following  branches:  Visceral,  muscular,  superior  gluteal, 
pudic,  small  sciatic,  and  great  sciatic. 

The  great  sciatic  is  a  continuation  of  the  main  part 
of  the  sacral  plexus,  forming  the  largest  nerve  in  the  body. 
It  supplies  nearly  the  whole  integument  of  the  leg,  the 
muscles  of  the  back  of  the  thigh,  and  those  of  the  leg  and 
foot.  At  the  lower  third  of  the  thigh  it  divides  into  two 
branches,  the  internal  and  external  popliteal  nerves. 

The  internal  popliteal  nerve  is  a  branch  from  the  great 
sciatic.  This  nerve  with  its  branches  supplies  the  pos- 
terior part  of  the  leg;  it  finally  divides  into  the  internal 
and  external  plantar  which  supply  the  foot. 

The  external  popliteal  is  smaller  than  the  internal;  it 
supplies  the  posterior  muscles  of  the  leg,  and  divides  into 
two  branches — the  anterior  tibial  and  musculocutaneous. 


THE   NERVOUS  SYSTEM  229 

The  anterior  tibial  supplies  the  tibial  artery  and  the  several 
muscles  of  the  anterior  part  of  the  leg,  and  furnishes 
branches  to  the  foot  and  the  articulation  of  the  tarsus  and 
metatarsus.  The  musculocutaneous  nerve  passes  down 
along  the  fibula,  supplying  the  peroneal  and  extensor 
muscles  of  the  foot;  the  internal  branch  supplies  the  ad- 
jacent parts  of  the  foot  and  toes;  the  external  supplies  the 
toes  and  communicates  with  the  external  saphenous  nerve. 

THE   GREAT   SYMPATHETIC   NERVE 

This  nerve  is  divided  into  two  portions:  the  vertebral 
and  the  prevertebral. 

The  vertebral  portion  is  divided  into  ganglia, 
which  unite  and  form  a  cord  running  longitudinally;  it 
passes  alongside  the  vertebral  column  from  the  head  to 
the  coccyx,  communicates  with  the  spinal  and  cranial 
nerves,  and  distributes  branches  to  the  internal  organs 
and  viscera. 

The  prevertebral  portion  also  comprises  a  number 
of  ganglia  that  form  plexuses  in  the  head,  chest,  abdomen, 
and  pelvis. 

The  sympathetic  nerve,  as  has  been  previously  stated, 
communicates  with  the  cerebrospinal  nerves  immediately 
at  their  exit  from  the  cranium  and  vertebral  canal.  (See 
Fig.  114.) 

The  branches  accompany  the  arteries  that  supply  the 
several  organs,  and  form  plexuses  that  surround  the 
blood-vessels;  they  take  the  name  of  the  artery  they 
accompany.  All  the  parts  of  the  head,  neck,  and  trunk 
are  supplied,  some  of  them  exclusively,  by  branches  from 
the  sympathetic;  therefore  it  has  been  called  the  nerve  of 
"organic  life."  Since  it  contains  so  great  a  number  of 
ganglia,  which  is  evinced  from  the  disposition  it  has  to 
communicate  with  others  in  its  distribution,  it  has  also 


230      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 


been  termed  the  ganglionic  nerve.     Its  functions  has  been 
previously  described. 

The  Ganglia. — There  are  four  gangUa  in  the  head: 
the  ophthalmic,  sphenopalatine  (Meckel's),  otic  or  Ar- 
nold's, and  the  submaxillary;  three  in  the  neck:  superior. 

Fig.  114. — Diagrammatic  view 
of  the  sympathetic  cord  of  the 
right  side,  showing  its  connec- 
tions with  the  principal  cerebro- 
spinal nerves  and  the  main  pre- 
aortic plexuses.  (Reduced  from 
Quain's  Anatomy.) 

Cerebrospinal  Nerves:  VI.,  A 
portion  of  the  sixth  cranial  as  it 
passes  through  the  cavernous 
sinus,  receiving  two  twigs  from 
the  carotid  plexus  of  the  sym- 
pathetic nerve ;  O,  ophthalmic 
ganglion  connected  by  a  twig  with 
the  carotid  plexus  ;  M,  connection 
of  the  sphenopalatine  ganglion 
by  the  Vidian  nerve  with  the 
carotid  plexus ;  C,  cervical  plexus ; 
Br,  brachial  plexus ;  D  6,  sixth 
intercostal  nerve  ;  D  12,  twelfth  ; 
L  3,  third  lumbar  nerve  ;  Si,  first 
sacral  nerve  ;  S^,  third  ;  S $,  fifth  ; 
6>,  anterior  crural  nerve ;  Cr, 
great  sciatic :  Pn,  vagus  in  the 
lower  part  of  the  neck  ;  r,  recur- 
rent nerve  winding  round  the  sub- 
clavian artery. 

Sympathetic  Cord:  c,  Superior 
cervical  ganglion ;  c' ,  second  or 
middle;  ^".inferior;  from  each 
of  these  ganglia  cardiac  nerves 
(all  deep  on  this  side)  are  seen 
descending  to  the  cardiac  plexus  ; 
di,  placed  immediately  below  the 
first  dorsal  sympathetic  ganglion  ; 
d  6  \s,  opposite  the  sixth  ;  /  i,  first 
lumbar  ganglion;  eg,  the  termi- 
nal or  coccygeal  ganglion. 

Preaortic  and  Visceral  /"/fx- 
wj^j.- //,  pharyngeal,  and,  lower 
down,  laryngeal  plexus ;  pi,  pos- 
terior pulmonary  plexus  spreading 
from  the  vagus  on  the  back  of  the 
right  bronchus  ;  ca,  on  the  aorta, 
the  cardiac  plexus,  toward  which, 
in  addition  to  the  cardiac  nerve 
from  the  three  cervical  sympa- 
thetic ganglia,  other  branches  are 


THE  NERVOUS  SYSTEM  23  I 

middle,  and  inferior  cervical;  twelve  in  the  dorsal  region; 
four  in  the  lumbar  region,  and  four  in  the  sacral  region. 

Bach  ganglion  is  considered  as  a  distinct  center,  receiv- 
ing and  giving  branches  in  four  different  directions — viz., 
superior,  or  ascending,  to  communicate  with  the  ganglion 
above;  inferior,  or  descending,  to  communicate  with  the 
ganglion  below;  external,  to  communicate  with  the  spinal 
nerves ;  and  internal,  to  communicate  with  the  sympathetic 
filaments  of  the  opposite  side  and  become  distributed  to 
the  viscera. 

Fig.  114  illustrates  the  several  portions  of  the  sympa- 
thetic nerve.  As  has  been  said,  this  nerve  is  one  of  or- 
ganic life,  for  there  is  no  organ  in  the  whole  body  but 
becomes  affected  when  the  function  of  this  nerve  is  dis- 
turbed; from  this  it  may  be  seen  how  sympathy  exists 
between  the  several  structures ;  this  has  already  been  dealt 
with  in  another  part  of  this  chapter. 


seen  descending  from  the  vagus  and  recurrent  nerves;  co,  right,  or  posterior, 
and  co' ,  left,  or  anterior,  coronary  plexus ;  o,  esophageal  plexus  in  long 
meshes  on  the  gullet ;  sp,  great  splanchnic  nerve  formed  by  branches  from  the 
fifth,  sixth,  seventh,  eighth,  and  ninth  dorsal  ganglia;  +,  small  splanchnic 
from  the  ninth  and  tenth  ;  +  +,  smallest,  or  third,  splanchnic  from  the  elev- 
enth ;  the  first  and  second  of  these  are  shown  joining  the  solar  plexus,  so  ;  the 
third  descending  to  the  renal  plexus,  re ;  connecting  branches  between  the 
solar  plexus  and  the  vagi  are  also  represented — pn' ,  above  the  place  where 
the  right  vagus  passes  to  the  lower  or  posterior  surface  of  the  stomach  ',  pn" , 
the  left  distributed  on  the  anterior  or  upper  surface  of  the  cardiac  portion 
of  the  organ :  from  the  solar  plexus  large  branches  are  seen  surrounding 
the  arteries  of  the  celiac  axis,  and  descending  to  ms,  the  superior  mesenteric 
plexus;  opposite  this  is  an  indication  of  the  suprarenal  plexus;  below  re 
(the  renal  plexus)  the  spermatic  plexus  is  also  indicated ;  ao,  on  the  front  of 
the  aorta,  marks  the  aortic  plexus,  formed  by  nerves  descending  from  the 
solar  and  superior  mesenteric  plexuses  and  from  the  lumbar  ganglia ;  vti,  the 
inferior  mesenteric  plexus  surrounding  the  corresponding  artery  ;  hy,  hypo- 
gastric plexus  placed  between  the  common  iliac  vessels,  connected  above  with 
the  aortic  plexus,  receiving  nerves  from  the  lower  lumbar  ganglia,  and  dividing 
below  into  the  right  and  left  pelvic  or  inferior  hypogastric  plexuses  ;  pi,  the 
right  pelvic  plexus  ;  from  this  the  nerves  descending  are  joined  by  those  from 
the  plexus  on  the  superior  hemorrhoidal  vessels,  mi' ,  by  nerves  from  the 
sacral  ganglia,  and  by  visceral  nerves  from  the  third  and  fourth  sacral  spinal 
nerves,  and  there  are  thus  formed  the  rectal,  vesical,  and  other  plexuses, 
which  ramify  upon  the  viscera,  as  toward  ir,  and  v,  the  rectum  and  bladder. 


232      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 


1 


REVIEW   QUESTIONS 

What  constitutes  the  nervous  system? 
What  is  the  brain,  and  of  how  many  parts  does  it  consist? 
What  is  the  average  weight  of  the  brain? 
What  membranes  surround  the  brain?     Name  them. 
Describe  the  several  membranes  of  the  brain. 
What  part  of  the  brain  does  the  cerebrum  form? 
What  important  connection  has  the  arachnoid  membrane? 
What  is  the  relation  of  the  pia  mater? 
Give  the  relations  of  the  corpus  callosum. 

Where  is  the  cerebrum  located?  , 

How  does  the  medulla  oblongata  vary  from  the  cerebrum  as  to  sen-  ,, 

sitiveness?  ; 

Through  what  foramen  does  the  spinal  cord  pass?  \ 

What  is  the  average  length  of  the  spinal  cord?  j 

How  is  the  spinal  cord  divided?  ^ 

What  is  the  circle  of  Willis?  j 

What  are  sinuses,  and  what  are  their  functions?  \ 

How  many  pairs  of  nerves  are  there?  | 

How  many  pairs  originate  from  the  cranial  region?  ^ 

How  many  pairs  originate  from  the  spinal  cord? 
How  many  roots  do  the  spinal  nerves  have? 
What  is  considered  to  be  the  center  of  the  nervous  system? 
What  is  the  function  of  the  cerebrum?     Of  the  cerebellum? 
What  important  relation  has  the  medulla  oblongata? 
What  are  the  functions  of  the  spinal  nerves? 
Into  how  many  groups  are  nerves  divided? 

What  are  the  nerves  of  special  sensation?  ., 

What  are  the  nerves  of  general  sensation?  ^ 

What  are  the  nerves  of  motion? 
What  nerves  are  involved  in  respiration? 
What  is  the  sympathetic  nerve?     What  does  it  mamtain? 
What  are  ganglia? 

How  is  the  fifth  cranial  nerve  divided? 
What  is  the  nerve  of  smell?     Of  sight?     Of  taste? 
What  is  the  function  of  the  auditory  nerve? 
Give  the  function  of  the  glossopharyngeal  nerve. 
What  is  the  tenth  nerve  called? 
What  is  the  brachial  plexus?     How  is  it  constructed? 
What  is  the  function  of  the  intercostal  nerves? 
What  do  the  lumbar  nerves  form? 
What  parts  do  the  sacral  nerves  supply? 
What  is  an  eflferent  nerve?    An  alBferent  nerve? 


CHAPTER    VIII 

THE  GLANDULAR  SYSTEM 

Th^  glands  are  secretory  organs  of  diverse  character 
and  location.  Some  of  them,  as  the  liver  and  kidneys,  are 
large,  while  others,  such  as  the  conglobate  or  lymphatic 
glands,  are  quite  small.  The  mucous  membranes  that 
line  the  glands  also  perform  the  function  of  secretion,  for 
they  secrete  the  mucus  in  which  they  abound,  as  is  seen 
in  the  mouth,  nostrils,  throughout  the  alimentary  canal, 
and  in  the  urinary  organs.  We  will  now  consider  these 
structures,  and  also  some  of  the  soft  bulbous  organs  that 
perform  the  function  of  secretion. 

THE   LYMPHATIC    GLANDS 

The  lymphatic  glands  are  found  distributed  over  all  the 
body,  and  consist  of  numerous  small  globular  bodies  con- 
nected with  the  lymphatic  vessels. 

The  lymphatic  glands  are  most  commonly  called  con- 
globate glands.  They  have  no  excretory  duct  except  the 
continuation  of  the  lymphatic  vessels.  The  largest  of 
the  conglobate  glands  are  the  mesenteric,  inguinal,  and 
axillary  glands.  These  glands  are  not  believed  to  secrete 
material  into  the  lymphatic  system,  but  simply  to  alter 
the  character  of  the  fluid  passing  through  them.  In  this 
sense  they  are  considered  the  outposts  of  the  body,  de- 
fending it  against  injurious  substances  that  are  carried  into 
the  lymphatics.  When  poison  or  any  irritating  substance 
is  forced  into  the  system,  as  into  the  extremities,  these 

233 


234      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 


Skin  reflected. 
Pectoralis  jinxjor. 
Central  group  of  glands. 


Cephalic  7>ein. 


Fig.  115. — Central  (superficial)  lymphatic  glands  of  the  axilla  (after  Leaf). 


Inferior  constrictor. 

'd 

Sternothyroid 

Internal j'ugula  r 
vein. 

Sternohyoid 


Small  occipital 
nerve. 


Posterior  belly  of 

digastric. 
Stylohyoid. 

?  eat  auricular 
ner7>e. 
enius. 


Levator  anguli 
scapula. 

Spinal  accessory 

nerve. 
Trapezius. 

Descending  branches 
of  cervical  plexus. 


Fig.  116.— Lymphatic  glands  of  the  head  and  neck  (after  Leaf). 

glands,   situated   between    the   entrance   of   the   poison 
and  the  body,  become  swollen  and  inflamed,  and  absorb 


THE    GLANDULAR   SYSTEM 


235 


the   foreign   substance    into    their  cells  and  retain  and 
neutralize   it;   or,   by   softening   and   suppuration,   they 


Fig.  117. — Diagram  of  a  lymphatic  gland,  showing  afferent  {a.  I.)  and 
efferent  {e.  I.)  lymphatic  vessels;  cortical  substance  {C)\  medullary  sub- 
stance {M) ;  fibrous  coat  {c) ;  sending  trabeculae  {tr)  into  the  substance  of 
the  gland,  where  they  branch,  and  in  the  medullary  part  form  a  reticulum; 
the  trabeculae  are  surrounded  by  the  lymph-path  or  sinus  (/.  s),  which  sepa- 
rates them  from  the  adenoid  tissue  (/.  h)  (Sharpey). 


"break  out,"   and  thus,  by  a  discharge,  expel  the  offen- 
sive material. 

THE   LIVER 

The  liver  occupies  part  of  the  right  hypochondriac 
and  part  of  the  epigastric  region,  immediately  below 
the  diaphragm.  It  is  the  largest  gland  in  the  body,  and 
weighs  about  4I  pounds.     It  is  lobular  in  form,  consisting 


236      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

mainly  of  two  large  and  two  smaller  lobes.  The  gall- 
bladder and  its  ducts  are  situated  on  the  under  surface  of 
the  liver.     This  organ  will  be  subsequently  described. 

Function  of  the  Liver.— Its  chief  function  is  to 
secrete  bile,  a  necessary  agent  in  the  process  of  digestion. 
It  also  forms  glycogen,  assists  in  the  formation  of  urea 
and  allied  products,  and  modifies  the  blood  as  it  passes 
through  it. 

Bile  is  both  a  secretion  and  an  excretion ;  it  contains  but 
few  constituents  other  than  those  that  are  formed  in  the 
liver,  and,  as  has  been  said,  it  is  destined  to  play  an  im- 


Gastric 
surface. 

T.pap. 
T.  omen. 


Non-peritoneal 
surface. 
Imp.  supra-ren. 
{non-perit). 
Imp.  supra-ren. 
Imp.  renalis. 

Imp.  duodenalis. 

Impressio  celica. 


Itnpressio  pylorica. 
Fig.  118. — ^Posterior  and  inferior  surfaces  of  the  liver  (Nancrede). 


portant  part  in  the  process  of  nutrition.  The  other  secre- 
tions of  the  liver  are  waste  products  that  are  associated 
with  the  bile. 

The  color  of  the  liver  is  different  from  that  of  all  the 
other  glands.  It  is  dark  brown,  and  sometimes  stained 
yellow  with  bile. 

Blood=suppIy. — The  liver  is  abundantly  supplied 
with  blood,  and  this  blood  is  modified  very  materially  in 
its  passage  through  the  gland. 

The  blood-vessels  that  enter  the  liver  are  the  portal 
vein,  made  up  of  the  gastric,  splenic,  superior,  and  inferior 
mesenteric  veins.     The  hepatic  artery  supplies  the  re- 


THE    GLANDULAR   SYSTEM  23/ 

quired  amount  of  blood  to  the  structure;  the  hepatic 
veins,   originating  in  the  interior,   collect  all  the  blood 


Intralobular 
vein. 

Branch  of 
portal  vein. 
Bile-dtict. 
Branch  of 

hepatic 

artery. 
Interlobular 

connective 

tissue. 


Fig.  119. — Section  through  liver  of  pig,  showing  chains  of  liver-cells;  X70 
(Bohm  and  Davidoff ). 


distributed  by  the  portal  vein  and  hepatic  artery  and  con- 
duct it  to  the  ascending  vena  cava. 

THE   GALL-BLADDER 

The  gall-bladder  is  a  pear-shaped  sac,  about  4  inches 
in  length,  situated  in  the  sinus  of  the  liver.  It  is  a  reser- 
voir for  the  bile,  and  is  capable  of  holding  about  ij 
ounces  of  fluid.  It  is  made  up  of  three  coats — a  serous, 
a  fibrous,  and  a  mucous. 

THE   SPLEEN 

The  spleen  is  an  oblong  gland  situated  in  the  left  hypo- 
chondriac   region,    immediately    below    the    diaphragm. 


238      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

It  is  of  a  spongy  texture  and  of  a  reddish  or  violet  color, 
about  5  inches  in  length,  and  weighs  6  ounces. 


Fig.  120. — Diagram  of  a  segment  of  a  hepatic  lobule :  i,  i,  Interlobular 
portal  vein;  2,  central  vein;  3,  3,  intralobular  capillaries;  4,  4,  interlobular 
hepatic  artery;  5,  5,  ramifications  of  hepatic  artery,  contributing  to  the 
formation  of  the  intralobular  capillaries ;  6,  6,  interlobular  bile-duct ;  7,  7, 
its  ramifications  in  the  lobule,  forming  a  plexus  of  intercellular  canaliculi ; 
8,  8,  section  of  biliary  canaliculi  with  their  intercellular  capillaries;  9,  9, 
hepatic  cells ;  10,  10,  interlobular  lymphatics,  receiving  the  intralobular 
lymphatics;  11,  11,  12,  intralobular  connective  tissue  (Testut). 

Function  of  the  Spleen. — The  '  spleen  is  probably 
concerned  in   the   preparation   of  albuminous  food  for 


THE    GLANDULAR   SYSTEM 


239 


nutrition.  During  digestion  the  spleen  becomes  larger 
and  its  contents  are  increased  in  amount;  after  digestion 
it  gradually  diminishes  in  size,  returning  to  its  normal 
condition. 

It  is  probably  in  this  organ  that  the  red  corpuscles, 
after  having  fulfilled  their  function  in  the  blood,   are 


Fig.  121. — Portion  of  gall-bladder  and  bile-ducts:  i,  Cavity  of  gall- 
bladder; 2,  cavity  of  calyx;  3,  groove  separating  the  calyx  from  the  blad- 
der ;  4,  promontory ;  5,  superior  valve  of  calyx  ;  6,  cystic  canal ;  7,  common 
bile-duct;  8,  hepatic  duct  (Testut). 


disintegrated,  for  the  splenic  venous  blood  contains 
relatively  a  small  number  of  them.  The  white  cor- 
puscles, however,  appear  to  be  increased  in  number, 
for  the  blood  of  the  splenic  vein  contains  an  unusually 
large  proportion.  The  spleen  serves  also  as  a  reservoir 
for  the  blood  when  the  portal  circulation  becomes 
obstructed. 


240      ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

Certain  it  is  that  this  gland,  like  the  conglobate  glands, 
under  some  forms  of  disease  (for  instance,  those  that 
result    from    infections,    particularly    malaria)    becomes 


Blood-vessel. 
-  Trabecula. 

-spleen  pulp. 


'■^'^vUp.—  Artery. 


Malpighian  cor- 
puscle with 
germ  center. 


Fig.  122. — Part  of  a  section  through  the  human  spleen:  X  75  (sublimate 
fixation).  At  a  is  an  oblong  Malpighian  body  with  a  blood-vessel  (Bohm 
and  Davidoff ). 

inflamed  and  often  indurated  and  swollen,  thus  exhibiting 
its  office  in  modifying  the  character  of  some  of  the  materials 
of  the  blood. 


THE    GLANDULAR   SYSTEM 


241 


THE   PANCREAS 

The  pancreas  is  an  oblong,  soft,  glandular  body,  situ- 
ated transversely  across  the  posterior  wall  of  the  abdo- 
men, in  the  left  hypochondriac  region,  just  behind  the 
stomach.  It  is  about  6  inches  long,  and  weighs  about  4 
ounces.     Its  office  is  to  secrete  the  pancreatic  juice. 


Fig.  123. — Pancreas  dissected  to  show  (a?. /.)  pancreatic  duct;  d.p.a, 
accessory  duct;  d.  ch,  bile-duct.  Duodenum  laid  open  to  show  (/.  m.) 
papilla  major;  /.  /,  papilla  minor;  spL,  spleen;  k,  kidney;  y,  jejunum ;  m. 
V,  mesenteric  vessels;  c.  a,  celiac  axis  (Robson  and  Moynihan). 


which  performs  a  part  in  the  digestive  process.  The 
function  of  the  pancreatic  juice  is  to  convert  starch  into 
maltose  and  albuminoids  into  peptones;  it  also  effects  the 
emulsification  of  fats. 


THE   PAROTID    GLANDS 

These  are  situated  in  front  of  the  lower  portion  of  the 
ear,  just  above  the  angle  of  the  jaw,  one  on  each  side. 
They  are  small,  soft  bodies,  and  their  office  is  to  secrete 
the  saliva,  which  affords  the  necessary  moisture  to  the 
mouth  and  the  requisite  fluid  for  the  process  of  mastica- 
tion.    The  saliva  is  also  an  important  agent  in  the  func- 

16 


242      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

tion  of  digestion.  The  practice  of  diluting  the  food  with 
large  quantities  of  water  while  eating  is  injurious,  for 
drinking  at  such  times  prevents  the  flow  of  saliva  into  the 
mouth  that  would  otherwise  take  place. 


Fig.  124. — Excretory  ducts  of  the  pancreas :  A,  Pancreas,  with  a,  its 
head;  B,  duodenum;  C,  jejunum;  D,  gall-bladder,  i,  main  pancreatic 
duct  of  Wirsung ;  2,  accessory  duct  with  2',  its  opening  upon  the  postero- 
internal wall  of  the  duodenum ;  3,  ampulla  of  Vater ;  4,  common  bile-duct; 
5,  cystic  duct;  6,  hepatic  duct;  7,  aorta;  8,  superior  mesenteric  vessels;  9, 
celiac  axis  with  its  three  branches  (Testut). 


The  salivary  duCt  opens  into  the  mouth  opposite  the 
second  molar  tooth  in  the  upper  jaw.  This  is  the  gland 
that  is  affected  in  the  disease  known  as  mumps  (epidemic 
parotitis). 


THE   GLANDULAR  SYSTEM 
THE   SUBMAXILLARY    GLANDS 


243 


These  glands  are  situated  on  the  inner  side  of  the  lower 
jaw — one  on  each  side  of  the  mouth  anterior  to  the  angle 
of  the  jaw.     Their  excretory  ducts  open  into  the  mouth 


Fig.  125.  Dissection  of  the  side  of  the  face,  showing  the  salivary  glands: 
a.  Sublingual  gland ;  b,  submaxillary  gland,  with  its  duct  opening  on  the 
floor  of  the  mouth  beneath  the  tongue  at  d\  c,  parotid  gland  and  its  duct, 
which  opens  on  the  inner  side  of  the  cheek  (after  Yeo). 


on  each  side  of  the  frenum,  or  "thread"  (bridle),  of  the 
tongue.  The  fluid  secreted  by  them  may  sometimes  be 
seen  to  ooze  forth  when  the  mouth  is  open,  especially 
when  the  mind  is  allowed  to  dwell  on  the  eating  of  fruits. 

THE    SUBLINGUAL    GLANDS 

The  sublingual  glands  are  situated  beneath  the  tongue, 
within  the  lower  jaw,  one  on  each  side  of  the  "thread" 
of  the  tongue.  They  are  small,  elongated  bodies,  and 
lie  immediately  under  the  mucous  membrane  of  the  floor 
of  the  mouth.  They  have  a  number  of  ducts  or  openings 
that  freely  discharge  the  fluid  secretion  of  the  glands. 
Their  function  is  similar  to  that  of  the  parotid  glands. 


244     ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

THE  THYROID   GLAND 

This  is  a  small,  flat,  glandular  body  lying  against  the 
anterior  surface  of  the  trachea,  below  the  thyroid  cartilage. 
It  is  susceptible  of  great  enlargement,  and  is  often  found 
abnormally  enlarged,  especially  in  women.  This  enlarge- 
ment constitutes  the  disease  called  goiter,  bronchocele, 
and  sometimes  "big  neck." 


Foramen  cecum. 

Lingual  duct. 
Epiglottis. 


Thyroid  gland. 


Trachea. 


Fig.  126. — The  thyroglossal  duct  (Marshall). 

The  thyroid  gland,  although  supplied  with  four  large 
arteries  and  veins  and  also  with  four  nerves,  has  no  excre- 
tory duct  that  has  yet  been  discovered.  Its  function  has 
never  been  thoroughly  understood. 


THE   LACRIMAL   GLANDS 

These  two  small  glands,  which  are  situated,  one  upon 
each  side,  in  a  depression  in  the  frontal  bone  at  the  upper 
and  outer  angle  of  the  orbit.     (See  Fig.  127.) 


THE    GLANDULAR   SYSTEM 


245 


The  size  of  the  lacrimal   glands   is  about  that  of  the 
kernel   of   a   peach-stone.     They  have   many   excretory 


Fig.  127. — Lacrimal  and  Meibomian  glands,  the  latter  viewed  from  the 
posterior  surface  of  the  eyehds  (the  conjunction  of  the  upper  lid  has  been 
partially  dissected  off,  and  is  raised  so  as  to  show  the  Meibomian  glands 
beneath) :  i.  Free  border  of  upper,  and  2,  free  border  of  lower  lid,  with 
openings  of  the  Meibomian  glands;  5,  Meibomian  glands  exposed,  and  6, 
as  seen  through  conjunctiva;  7,  4",  lacrimal  gland;  9,  its  excretory  ducts, 
with  10,  their  openings  in  the  conjunctival  cul-de-sac;  11,  conjunctiva. 

ducts,  which  open  into  the  eye  under  the  upper  lid. 
Their  function  is  to  furnish  moisture  to  the  eyes;  these 
are  the  organs  which  secrete  the  tears. 


THE  MESENTERIC  GLANDS 
These  glands  are  small,  knot-like  bodies,  occurring  in  the 
course  of  the  chyliferous  vessels  in  the  mesentery.  They 
are  very  numerous,  but  have  no  excretory  duct.  The 
lacteals,  however,  as  stated  in  a  previous  chapter,  pass 
through  them.  It  is  not  known  certainly  to  what  extent 
the  chyle,  conveyed  through  the  glands  by  the  lacteals, 
is  modified;  and  hence  the  office  of  the  mesenteric  glands 
is  as  yet  but  little  understood. 


246      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

THE   mi<MiAKSC{   GLANDS 

The  mammary  glands,  which  secrete  the  milk,  are  two 
more  or  less  hemispheric  organs,  situated  in  the  human 
female  on  the  anterior  surface  of  the  chest.  Though 
rudimentary  in  childhood,  they  gradually  increase  in  size 
as  the  female  approaches  puberty. 


Fig.  128. — Mammary  glands:  i,  Lacteal  ducts;   2,  glandular  acinus  (after 

Playfair). 


The  gland  presents  at  its  convexity  a  small  prominence 
of  skin,  the  nipple,  which  is  surrounded  by  a  circular 
area  of  pigmented  skin,  the  areola.  The  gland  proper 
is  covered  anteriorly  by  a  layer  of  adipose  tissue,  and 
attached  posteriorly  to  the  pectoral  muscles  by  a  meshwork 
of  fibrous  tissue. 


THE    GLANDULAR   SYSTEM  24/ 

Changes  in  the  Mammary  Glands. — During  preg- 
nancy the  mammary  glands  become  larger,  firmer,  and  more 
lobulated ;  the  areola  darkens,  and  the  veins  become  more 
prominent.  During  the  period  of  lactation  the  gland  is 
the  seat  of  active  histologic  and  physiologic  changes  cor- 
related with  the  production  of  milk.  At  the  close  of 
lactation  the  glands  diminish  in  size,  undergo  involution, 
and  gradually  return  to  their  original,  non-secreting  con- 
dition. 

Structure  of  the  Mammary  Glands.— Each  gland  con- 
sists of  an  aggregation  of  some  fifteen  to  twenty  lobes, 
each  of  which  is  surrounded  by  a  framework  of  fibrous 
tissue.  The  lobe  is  provided  with  an  excretory  duct, 
which,  as  it  approaches  the  base  of  the  nipple,  expands 
to  form  a  sinus  or  reservoir,  beyond  which  it  opens  by 
a  narrowed  orifice  on  the  surface  of  the  nipple.  On 
tracing  the  dijct  into  the  lobe  it  is  found  to  divide  and 
subdivide,  and  finally  to  terminate  in  lobules  or  acini. 
Each  acinus  consists  of  a  basement  membrane,  lined  by 
cells,' and  supplied  with  blood-vessels,  lymphatics,  and 
nerves. 

THE   SEBACEOUS   GLANDS 

The  sebaceous  glands  are  embedded  in  the  true  skin, 
and  consist  of  grape-like  masses  opening  by  a  duct  upon 
the  surface  of  the  epidermis  or  into  a  hair-follicle.  They 
are  found  in  almost  every  part  of  the  body,  but  most 
abundantly  upon  the  face.  They  secrete  an  oily  sub- 
stance, known  as  sebum.  It  is  obstruction  of  these  ducts 
that  produces  what  are  commonly  known  as  "black- 
heads," which  are  seen  so  often  upon  the  face. 

The  deposit,  so  abundant  upon  some  children  at  birth, 
and  which  consists  of  a  white,  glue-like  substance,  is  the 
residue  of  the  sebaceous  matter,  and  is  known  as  the 
vernix  caseosa. 


248     ANATOMY  AND  PHYSIOLOGY  FOR  NURSES. 


Fig.  129. — Sebaceous  glands  of  the  face — simple  pouch  to  compound 
lobular,  with  lanugo  hair  and  small  or  rudimentary  hair-follicle,  the  largest 
from  the  nose  (Sappey). 


THE    GLANDULAR   SYSTEM 


249 


THE   SUDORIPAROUS    GLANDS 

The  sudoriparous  glands  excrete  the  sweat.  They 
consist  of  minute  openings,  commonly  called  the  pores 
of  the  skin.  Their  function  is  to  extract  from  the  blood 
the  excrementitious  material  (this  function  has  been 
described  in  a  previous  chapter).  It  is  estimated  that 
the  daily  excretion  from  these  glands  amounts  to  about 
2  pounds,  although  it  varies  according  to  the  nature  of 
the  food  and  drink  taken,  the  amount  of  exercise,  external 
temperature,  season,  etc. 


Fig.  130. — Sweat-glands  of  different  size  (of  moderate  magnification), 
showing  coil  or  convolutions  forming  gland  proper,  the  bUnd  end  of  tubule, 
and  excretory  duct  (Sappey). 


The  secretion  of  sweat  is  regulated  by  the  nervous  sys- 
tem. Here,  as  in  the  secreting  glands,  the  fluid  is  formed 
from  material  in  the  lymph-spaces  surrounding  the 
glands.  Two  sets  of  nerves  are  concerned:  Vasomotor, 
regulating  the  blood-supply;  and  secretory,  stimulating 
the  activities  of  the  gland-cells.  Generally,  the  two 
conditions,  increased  blood-flow  and  increased  glandular 
action,  coexist.  At  times  a  profuse,  clammy  perspiration 
occurs  with  a  diminished  blood-flow. 


250      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

Besides  the  glands  already  described,  many  others  of 
minor  importance  occur.  For  a  description  of  these,  the 
reader  is  referred  to  the  more  extensive  works  on  anatomy. 

REVIEW    QUESTIONS 

What  are  glands? 

What  are  lymphatic  glands?     What  is  their  function? 
Which  is  the  largest  gland  of  the  body?     Where  is  it  located? 
How  many  lobes  are  there  in  the  liver? 
What  is  the  function  of  the  liver? 
What  large  vein  enters  the  liver? 
What  artery  supplies  the  liver? 
What  is  the  average  weight  of  the  liver? 
What  is  the  gall-bladder? 
What  is  the  function  of  the  bile? 
What  is  the  capacity  of  the  gall-bladder? 
Where  is  the  spleen  situated,  and  what  is  its  function? 
What  is  the  pancreas?     Its  function? 
What  is  the  function  of  the  pancreatic  juice? 
Where  are  the  parotid  glands  situated,  and  what  is  their  function? 
What  disease  is  liable  to  attack  them? 

What  duct  carries  the  secretion  from  this  gland,  and  where  does  it 
open? 

Give  location  of  the  submaxillary  glands.     What  is  their  function? 

Give  location  of  sublingual  glands. 

What  is  the  thyroid  gland?     State  location. 

To  what  disease  is  this  gland  most  susceptible? 

What  is  the  prostate  gland? 

Give  the  function  of  the  lacrimal  glands  and  state  their  location. 

Where  do  we  find  the  mesenteric  glands?     What  is  their  function? 

What  are  the  mammary  glands?     Where  situated? 

What  are  the  functions  of  these  glands? 

What  changes  take  place  in  these  glands? 

Describe  the  structure  of  the  mammary  glands. 

What  are  the  sebaceous  glands? 

Describe  the  location  of  the  sudoriparous  glands. 

How  is  the  secretion  of  the  various  glands  regulated? 


CHAPTER    IX 
THE  MEMBRANES  OF  THE  BODY 

Thb  mucous  membrane  is  the  proper  lining  of  the 
ahmentary  canal,  the  respiratory,  the  urinary,  and  the 
genital  organs.  It  is  of  a  glandular  construction,  and  in 
some  parts  secretes  mucus  copiously.  This  membrane, 
like  the  skin,  has  numerous  openings  upon  its  surface, 

^^^^^^^^^^^^   ■ 

Fig.  131. — Plan  of  a  secreting  membrane  (Howell). 

through  which  a  large  amount  of  fluid  materials  are  re- 
moved, as  is  seen  in  diarrhea  and  dysentery.  The  urinary 
bladder,  which  is  of  a  fibrous  texture  in  its  main  con- 
struction, has  a  thick  mucous  membrane  that  protects  the 
organ  against  irritation  from  the  acrid  substances  in  the 
urine. 

The  serous  membranes  are  found  on  internal  surfaces 
that  have  no  outlets,  as  the  pleura,  peritoneum,  pericar- 
dium, and  the  brain.  These  membranes  serve  to  support, 
in  their  various  places  and  positions,  the  several  organs 
they  invest. 

The  pericardium  forms  a  sac  enclosing  the  heart;  the 
peritoneum  invests  the  contents  of  the  abdominal  cavity; 
and  the  pleura  forms  two  sacs  to  support  the  lungs.  They 
all  secrete  a  fluid  for  their  lubrication. 

From  the  serous  membranes  a  serous  or  watery  fluid 
is  exuded,  which  affords  a  moist  and  smooth  surface  for 

251 


252      ANATOMY  AND  PHYSIOLOGY  FOR   NURSES 

the  play  of  the  several  organs  upon  them.  These  mem- 
branes are  of  a  light-red  color  and  well  supplied  with 
blood-vessels.  In  some  places  they  are  liable  to  serious 
inflammation,  often  forming  adhesions  to  other  organs. 

Synovial  membranes  resemble  the  serous  membranes 
in  structure,  but  differ  from  them  in  the  nature  of  their 
secretion,  which  in  the  former  is  thick,  viscid,  and  glairy, 
like  the  white  of  an  ^gg,  hence  called  synovia. 

Synovial  membrane  is  a  thin,  delicate  membrane, 
arranged  in  the  form  of  a  short,  wide  tube,  attached  by  its 
open  ends  to  the  margins  of  the  articular  extremities  of 
the  bones,  and  covering  the  inner  surface  of  the  various 
ligaments  that  connect  the  articulating  surfaces. 

The  synovial  membranes  found  in  the  body  admit  of 
subdivision  into  three  kinds — articular,  bursal,  and  vagi- 
nal. The  articular  synovial  membranes  are  found  in  all 
movable  joints;  the  bursce  are  found  interposed  between 
surfaces  that  move  upon  each  other,  producing  friction, 
as  the  gliding  of  a  tendon  or  of  the  integument  over  pro- 
jecting surfaces;  the  vaginal  serve  to  facilitate  the  gliding 
of  tendons  in  the  osseofibrous  canals,  through  which  they 
pass,  as  in  the  hand  and  foot. 

The  membranes  of  the  brain  have  been  described  in  the 
chapter  on  the  Nervous  System. 

REVIEW   QUESTIONS 

What  kind  of  membranes  have  we  in  the  body? 

What  cavities  are  lined  by  mucous  membranes? 

Name  the  serous  membranes. 

What  are  synovial  membranes?     Note  the  varieties. 

What  membrane  lines  the  heart? 

What  membrane  surrounds  the  lungs? 

What  is  the  function  of  the  serous  membranes? 


CHAPTER    X 

THE  ORGANS  OF  SPEQAL  SENSE 

THE   ORGANS   OF   SIGHT 

The  eyes  are  two  globular  bodies,  situated  one  in  each 
orbit.  They  are  the  organs  of  vision,  and  are  enclosed 
partly  by  the  lids  and  partly  by  the  bony  sockets. 

The  eyeball  is  composed  of  several  tunics  or  coats.  In 
front  we  have  the  conjunctiva,  then  the  sclerotic  coat,  or 

upper  lid-border. 


Iris  with  corneal 

rejlex  anterior. 

Hclera. 


Lower  lid-border. 
Fig.  132. — The  anterior  surface  of  the  eyeball  (Pyle). 

white  firm  structure  that  surrounds  all  the  ball  except 
the  front,  where  the  cornea  takes  its  place.  The  cornea 
is  a  transparent  structure  that  admits  the  rays  of  light  for 
vision.  Then  follow  the  choroid  coat,  iris,  and  ciliary 
processes,  together  constituting  the  second  or  middle  coat 
of  the  eyeball.  The  humors  or  fluids  are  the  aqueous, 
crystalline,  and  vitreous. 

The  sclerotic  coat  is  a  dense,  fibrous  layer  that  in- 
vests about  the  posterior  five-sixths  of  the  globe  of  the  eye. 

253 


254     ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

It  gives  form  to  this  organ,  and  serves  for  the  attach- 
ment of  the  muscles  that  move  the  eye  in  various  direc- 
tions. This  coat,  from  the  briUiancy  of  its  whiteness,  is 
known  as  "the  white  of  the  eye."  Anteriorly,  the  sclerotic 
coat  presents  a  beveled  edge,  which  receives  the  cornea 
in  the  same  way  that  a  watch-glass  is  received  by  the 
groove  in  the  case. 

The  cornea  is  the  transparent  projecting  layer  that 
forms  the  anterior  sixth  of  the  globe  of  the  eye.     In 


k  I 

Fig.  133 — ^Vertical  section  through  the  eyeball :  a.  Sclera ;  b,  choroid ;  c, 
ciliary  muscle ;  d,  iris  ;  e,  cul-de-sac  of  conjunctiva ;  /,  anterior  chamber 
and  aqueous  humor;  g,  crystalline  lens  ;  h,  posterior  chamber  ;  i,  angle  of 
anterior  chamber  ;  /,  suspensory  ligament  of  lens  ;  k,  cornea ;  /,  vitreous ; 
m,  optic  nerve  with  central  artery  of  retina ;  n,  retina ;  0,  0',  ocular  muscles 
(Pyle). 


form  it  is  circular,  convexoconcave,  and  resembles  a 
watch-glass.  It  is  received  by  its  edge,  which  is  sharp 
and  thin,  within  the  beveled  border  of  the  sclerotic,  to 
which  it  is  firmly  attached.  The  cornea  is  composed  of 
several  different  layers;  its  blood-vessels  are  so  small  that 
they  exclude  the  red  particles  altogether  and  admit  noth- 
ing but  serum. 

The  choroid  coat  is  a  vascular  structure,  of  a  rich, 
chocolate-brown  color  upon  its  external  surface,  and  of  a 


THE    ORGANS   OF  SPECIAL   SENSE  25  ^ 

deep-black  color  within.  It  is  connected  externally  with 
the  sclerotic,  by  an  extremely  fine  cellular  tissue  and  by 
the  passage  of  the  nerves  and  vessels ;  internally,  it  is  in 
contact  with  the  retina.  The  choroid  membrane  is  com- 
posed of  three  layers.  It  secretes  upon  its  internal  sur- 
face a  dark  substance,  called  pigmentum  nigrum,  which  is 
of  great  importance  in  the  function  of  vision. 

The  iris,  so  called  from  the  variety  of  its  colors  in 
different  persons,  forms  a  partition  between  the  anterior 


Fig.  134 — Choroid  membrane  and  iris,  exposed  by  the  removal  of  the 
sclerotic  and  cornea:  a.  One  of  the  segments  of  the  sclerotic  thrown  back; 
d,  ciliary  muscle;  c,  iris;  e,  one  of  the  ciliary  nerves;  /,  one  of  the  vasa 
vorticosa  or  choroidal  veins  (Zinn). 


and  posterior  chambers  of  the  eye,  and  is  pierced  by  a  cir- 
cular opening  called  the  pupil.  It  is  composed  of  two 
layers.  The  radiating  fibers  of  the  anterior  layer  converge 
from  the  circumference  to  the  center.  Through  the  ac- 
tion of  these  radiating  fibers  the  pupil  is  dilated.  The 
circular  fibers  surround  the  pupil,  and  their  action  pro- 
duces contraction  of  the  area.  The  posterior  layer  is  of 
deep-purple  tint,  and  is  called  uvea,  from  its  resemblance 
in  color  to  a  ripe  grape. 

The  ciliary   processes  consist  of    a  number  of    tri- 


256      ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

angular  folds,  formed,  apparently,  by  the  plaiting  of  the 
internal  layer  of  the  choroid  coat;  they  are  about  sixty 
in  number.  Their  external  border  is  continuous  with  the 
internal  layer  of  the  choroid  coat.  The  central  border  is 
free,  and  rests  against  the  circumference  of  the  crystalline 
lens.  These  processes  are  covered  by  a  layer  of  pigmen- 
tum  nigrum. 

The  retina  is  composed  of  three  layers:  the  external, 
the  middle  or  nervous,  and  the  internal  or  vascular. 

The  external  layer  is  extremely  thin,  and  the  membrane 
is  seen  as  a  flocculent  film  when  the  eye  is  suspended  in 
water. 

The  nervous  membrane  is  the  expansion  of  the  optic 
nerve,  and  forms  a  thin,  semitransparent,  bluish-white 
layer.  The  vascular  membrane  consists  of  the  ramifica- 
tions of  a  minute  artery  and  its  accompanying  vein. 
The  vascular  layer  forms  distinct  sheaths  for  the  nervous 
papillae,  which  constitute  the  inner  surface  of  the  retina. 

The  aqueous  humor  fills  the  anterior  and  posterior 
chambers  of  the  eye.  It  is  an  albuminous  fluid,  having 
an  alkaline  reaction.  Its  specific  gravity  is  a  very  little 
greater  than  that  of  distilled  water.  The  anterior  chamber 
is  the  space  intervening  between  the  cornea  in  front, 
and  the  iris  and  the  pupil  behind ;  the  posterior  chamber  is 
the  narrow  space,  less  than  half  a  line  in  depth,  bounded 
by  the  posterior  surface  of  the  iris  and  pupil  in  front,  and 
by  the  ciliary  processes  and  crystalline  lens  behind.  The 
two  chambers  are  lined  by  a  thin  layer — the  secreting 
membrane  of  the  aqueous  humor. 

The  crystalline  humor,  or  lens,  is  situated  imme- 
diately behind  the  pupil,  and  is  surrounded  by  the  ciliary 
processes.  This  humor  is  more  convex  on  the  posterior 
than  on  the  anterior  surface,  and  in  different  portions  of 
the  surface  of  each  the  convexity  varies.  The  lens  is 
embedded  in  the  anterior  part  of  the  vitreous  humor,  from 


THE    ORGANS   OF  SPECIAL   SENSE 


257 


which  it  is  separated  by  a  thin  membrane;  it  is  invested 
by  a  transparent  elastic  membrane,  called  the  capsule  of 
the  lens.  The  lens  consists  of  concentric  layers  arranged 
like  the  coats  of  an  onion.  The  external  layer  is  soft,  and 
each  successive  one  increases  in  firmness  until  the  central 
layer  forms  a  hardened  nucleus.  These  layers  are  best 
demonstrated  by  boiling  or  by  immersing  in  alcohol, 
when  they  easily  separate  from  one  another. 


Fig.  135.— Crystalline  lens  and  suspensory  ligament  or  zonula:  i,  Lens; 
2,  posterior,  and  3,  anterior  portion  of  zonula ;  4,  its  insertion  into  the  pre- 
equatorial  region.  The  black  rays  are  lines  of  pigment  torn  from  the  ciliary 
processes,  and  belong  in  reality  to  the  ciliary  portion  of  the  retina  (Testut). 

The  vitreous  humor  forms  the  principal  bulk  of  the 
globe  of  the  eye.  It  is  an  albuminous  fluid,  resembling 
the  aqueous  humor,  but  is  denser,  and  differs  from  the 
aqueous  in  this  important  particular,  that  it  has  not  the 
power  of  reproducing  itself.  If,  therefore,  by  accident  it 
is  discharged,  the  eye  is  irrecoverably  lost;  whereas,  if  the 
aqueous  humor  is  discharged,  it  will  again  be  restored. 
The  vitreous  is  enclosed  in  a  delicate  membrane,  called  the 
hyaloid,  which  sends  processes  into  the  interior  of  the  globe 
of  the  eye,  forming  the  cells  in  which  the  humor  is  retained. 


17 


258      ANA  TOM  V  AND   PH YSIOL  OGY  FOR   NURSES 
THE   APPENDAGES   OF  THE   EYE 

The  appendages  of  the  eye  are  the  eyebrows,  eyeHds, 
eyelashes,  conjunctiva,  caruncula  lacrimaHs,  and  lacrimal 
apparatus. 

The  eyebrows  (supercilia)  are  two  prominent  arches 
of  integument,  covered  with  short,  thick  hairs,  which  form 
the  upper  boundary  of  the  orbits.  They  serve  to  shade 
the  eyes  from  a  too  vivid  light,  and  protect  them  from  the 
particles  of  dust  and  moisture  that  roll  down  the  forehead. 

The  eyelids  (palpebral)  are  two  valvular  layers 
placed  in  front  of  the  eye,  serving,  by  their  closure,  to 
defend  it  against  injury;  they  have  been  called  the  "blinds 
of  the  eye."  When  drawn  up,  they  disclose  an  elliptic 
space  {fissura  palpebrarum),  the  angle  of  which  forms  the 
outer  and  inner  canthi.  The  inner  canthus  is  prolonged 
for  a  short  distance  inward  toward  the  nose,  and  a  tri- 
angular space  is  formed  which  is  called  the  lacus  lachry- 
malis.  At  the  commencement  of  the  lacus  lachrymalis, 
upon  each  of  the  two  hds,  is  a  small,  angular  projection,  the 
papilla  or  tubercle ,  which  forms  the  entrance  to  the  lacrimal 
canal. 

The  tegumentary  areolar  tissue  of  the  eyehds  is  re- 
markable for  its  looseness  and  absence  of  fat ;  it  is  particu- 
larly liable  to  serous  infiltration  after  injury  to  these 
parts. 

The  tarsal  cartilages  contribute  to  the  support  of 
the  eyelids.  They  are  semilunar  in  form,  the  superior 
being  about  J  inch  in  breadth  at  its  middle  and  taper- 
ing toward  each  extremity.  The  inferior  is  an  elliptic 
band,  narrower  than  the  superior,  and  is  situated  in  the 
substance  of  the  lower  lid.  Its  upper  border  is  flat,  and 
corresponds  with  the  edge  of  the  upper  cartilage.  The 
lower  is  held  in  place  by  the  fibrous  membrane,  which  is 
firmly  attached  to  the  periosteum  around  the  margin  of 
the  orbit- 


THE   ORGANS   OF  SPECIAL  SENSE 


259 


The  Meibomian  glands  are  embedded  in  the  sub- 
stance of  the  cartilages,  and  are  distinctly  seen  on  examin- 
ing the  inner  aspect  of  the  lids.  They  have  the  appear- 
ance of  a  string  of  pearls,  and  are  about  thirty  in  number 
in  the  upper  cartilage,  and  somewhat  fewer  in  the  lower; 
they  open  by  minute  foramina  on  the  edges  of  the  lids. 
(See  p.  245.) 

The  edges  of  the  eyelids  are  provided  with  a  row  of 
long,  thick  hairs  (eyelashes)  that  curve  upward  from  the 


Fig.  136. — Right  eye  from  before,  the  eyelids  separated  by  hooks :  Ps, 
Plica  semilunaris;  Ph,  Pli,  superior  and  inferior  lacrimal  puncta;  Car, 
lacrimal  caruncle  •,  Lj>m,  internal  tarsal  ligament. 

upper  lid  and  downward  from  the  lower,  so  as  not  to  inter- 
lace with  one  another  when  the  eyelids  close. 

The  conjunctiva  is  the  mucous  membrane  of  the  eye. 
It  covers  the  whole  anterior  surface,  with  the  exception  of 
the  cornea,  which  it,  however,  provides  with  an  epithelial 
layer,  and  is  reflected  backward,  upward,  and  downward 
upon  the  lids  so  as  to  form  their  internal  layer. 

The  caruncula  lacrimalis  is  a  small,  reddish  body 
that  occupies  the  inner  canthus  of  the  eye.  In  health  it 
presents  a  bright-pink  tint;  in  sickness  it  loses  its  color  and 
becomes  pale. 


26o      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

The  nasal  duct,  a  part  of  the  lacrimal  apparatus,  is 
a  short  canal,  about  f  inch  in  length,  directed  downward, 
backward,  and  a  little  outward  to  the  inferior  mea- 
tus of  the  nose,  where  it  terminates  by  an  expanded  ori- 
fice. It  is  provided  with  a  mucous  membrane,  continu- 
ous with  the  conjunctiva  above  and  with  the  membrane 
of  the  nose  below.  Obstruction  of  this  duct  from  inflam- 
mation and  suppuration  leads  to  the  formation  of  a 
lacrimal  fistula.  The  nerves  and  vessels  are  derived 
from  the  ophthalmic  branches. 

PHYSIOLOGY   OF  VISION 

After  reviewing  the  anatomic  relation  of  sight,  we  will 
now  take  up  a  few  essential  points  regarding  the  physio- 
logic action  of  the  various  structures. 

It  is  by  the  sense  of  sight  that  we  receive  the  impres- 
sion of  light  and  color,  as  well  as  the  ideas  of  construction 
of  materials,  establishing  certain  fancies,  likes,  and  dis- 
likes of  the  external  surroundings. 

The  eyeball  is  constructed  like  a  photographer's  camera. 
The  sclerotic  and  choroid  coats  correspond  to  the  inside 
walls  of  the  chamber,  while  by  the  refractive  power  of 
the  several  parts,  as  the  cornea,  aqueous  humor,  crystal- 
line lens,  and  vitreous  humor,  the  image  is  formed.  The 
retina  represents  the  sensitive  plate  on  which  the  image  is 
received.  The  iris  regulates  the  rays  of  light,  acting  as 
a  diaphragm  to  cut  out  certain  portions  of  light  that  are 
not  required.  The  ciliary  muscles  adjust  the  shape  of 
the  crystalline  lens  so  as  to  focus  images  upon  the 
retina. 

The  function  of  the  crystalline  lens  is  to  focus  the  rays 
of  light  with  the  formation  on  the  retina  of  the  image, 
corresponding  with  the  object  from  which  the  light  pro- 
ceeds. By  accommodation  is  meant  the  power  of  adjusting 
the  eye  to  certain  distances.     A  normal  eye  does  not 


THE    ORGANS   OF  SPECIAL   SENSE  26 1 

require  adjustment  for  parallel  rays,  but  for  divergent 
rays  a  change  in  the  eye  is  necessary;  the  ability  to  make 
this  change  is  known  as  the  power  of  accommodation. 

The  astigmatic  eye  is  so  called  from  the  inabikty.  to 
focus  vertical  and  horizontal  lines  at  the  same  tijie.  This 
is  usually  due  to  some  irregularity  of  the  curvj^ire  of  the 
refracting  surfaces  of  the  eye,  and  a  cylindric  lens  is  Re- 
quired to  correct  the  defect. 

Myopia,  or  short-sightedness,  is  a  condition  caused'-^y 
an  increased  anteroposterior  diameter  of  the  eyebdll, 
causing  the  parallel  rays  of  light  to  focus  in  front  of  the 
retina.  Myopia  causes  diminution  of  distance  vision,  and 
requires  concave  lenses  to  correct  the  deficiency. 

Hyperopia,,  or  far-sightedness,  is  a  condition  of  refrac- 
tion of  the  eye  in  which,  when  the  accommodation  is  at 
rest,  the  focus  of  the  parallel  rays  of  lighjt  transmitted 
through  the  eye  is  beyoiH  the  retina.  Convex  glasses  are 
required  to  correct  this  defect. 

Presbyopia  is  a  condition  of  the  eye  in  which  the  power 
of  accommodation  is  partly  or  wholly  lost.  This  condi- 
tion occurs  in  the  aged,  usually  commencing  between  the 
ages  of  forty  and  fifty  years,  and  requires  convex  spheric 
lenses  for  its  correction. 

THE  ORGAN  OF  HEARING 
The  ear  is  the  organ  of  hearing,  and  consists  of  a  series 
of  cavities  so  arranged  as  to  receive  the  vibrations  (sounds) 
in  the  atmosphere,  and  convey  them  to  the  delicate  ner- 
vous membrane  within  its  structure.  The  ear  is  composed 
of  three  parts :  the  external  ear,  the  tympanum  or  middle 
ear,  the  labyrinth  or  internal  ear. 

The  external  ear  is  composed  of  two  parts — the  pinna 
(auricle  or  pavilion  of  the  ear)  and  the  external  auditory 
meatus  (auditory  canal). 

The  pinna  is  a  cartilaginous  plate  that  surrounds  the 


262      ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 


entrance  of  the  auditory  canal.  It  presents  several  ridges 
and  furrows,  arising  from  the  folds  of  the  cartilages  that 
form  it. 

The  external  auditory  meatus  is  a  canal,  partly  cartilag- 
inous and  partly  bony,  about  i  inch  in  length,  whose  walls 
extend  inward  from  the  pinna  to  the  membrana  tympani, 
or  drum  of  the  ear.  It  is  narrower  in  the  middle  than  at 
the  extremities.  It  is  lined  by  an  extremely  thin  pouch 
of  cuticle,  which,  when  withdrawn  after  maceration,  pre- 
serves the  form  of  the  canal. 
Stiff,  short  hairs  that  stretch 
across  the  tube  are  often  found 
in  the  interior  of  the  channel, 
and  prevent  the  ingress  of  in- 
sects. Beneath  the  cuticle  are 
a  number  of  small  follicles  that 
secrete  the  wax  {cerumen)  of  the 
ear. 

The  membrana  tympani  is 
a  thin,  semitransparent  mem- 
brane of  an  oval  shape.  It  is 
about  8  inch  in  dimeter,  and  is 
inserted  into  the  groove  around 
the  circumference  of  the  meatus, 
This  membrane  is  placed  ob- 
it   is    concave    toward    the 


Fig.  137 — The  external 
ear:  a.  Helix;  b,  fossa  of 
anthelix ;  c,  tragus  ;  d,  lobule  ; 
e,  antitragus ;  f,  concha ;  g; 
anthelix;  h,  fossa  of  helix 
(Randall). 


near   its   termination. 

liquely   across   the    tube. 

meatus  and  convex  toward  the  tympanum. 

The  tympanum  is  an  irregular  bony  cavity,  situated 
within  the  temporal  bone.  It  is  bounded  externally  by 
the  membrana  tympani;  internally,  by  the  inner  wall; 
and  in  its  circumference,  by  the  petrous  portion  of  the 
temporal  bone  and  mastoid  cells.  The  tympanum  is 
traversed  by  a  chain  made  of  three  small  bones — the 
malleus,  incus,  and  stapes.     (See  Fig.  139.) 

The  mastoid  cells  are  very  numerous,  and  occupy  the 


THE    ORGANS   OF  SPECIAL   SENSE 


263 


whole  of  the  interior  of  the  mastoid  process  and  part  of 
the  petrous  portion  of  the  temporal  bone.     They  com- 


FlG.  138. — Semidiagrammatic  section  through  the  right  ear :  G,  external 
auditory  meatus;  7",  membrana  tympani  ;  P,  tympanic  cavity;  0,  fenestra 
ovalis;  r.  fenestra  rotunda;  B,  semicircular  canal;  ^.cochlea;  Vt,  scala 
^estibuli;  Pt,  scala  tympani  (Czermak). 

municate  with  the  upper  and  posterior  circumference  of 
the  tympanum  by  a  large  irregular  opening. 


Fig.  139. — The  small  bones  of  the  ear ;  external  view  (enlarged)  (after  Gray). 

The  Eustachian  tube  is  a  canal  of  communication,  ex- 
tending obliquely  between  the  pharynx  and  the  anterior 


264      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

circumference  of  the  tympanum.  In  structure  it  is  partly 
fibrocartilaginous  and  partly  bony.  It  is  broad  and  ex- 
panded at  its  pharyngeal  extremity,  and  narrow  and  com- 
pressed at  the  tympanum. 

The  nerve  supply  is  mainly  from  the  auditory  nerve. 

The  internal  ear,  or  labyrinth,  is  the  essential 
part  of  the  organ  of  hearing.  It  consists  of  three  parts — 
the  vestibule,  semicircular  canals,  and  cochlea.  It  receives 
the  ultimate  distribution  of  the  auditory  nerve.  It  is 
connected  with  the  middle  ear  by  two  openings,  the 
fenestra  rotunda  and  the  fenestra  ovalis. 

(The  nurse  will  do  well  to  devote  some  time  to  the 
study  of  these  l^rgans,  for  she  will  often  be  called  upon  to 
care  for  patients  in  whom  these  important  parts  are  dis- 
eased.) 

THE   ORGANS   OF   TASTE 

The  chief  organ  of  taste  is  the  tongue,  and  yet  the  palate 
and  lips  participate  in  receiving  the  impressions  made 
by  substances  taken  into  the  mouth.  These  impressions 
are  conveyed  to  the  brain  by  the  nerves,  and  thus  a  per- 
ception of  the  quality  of  the  taste  or  impression  on  the 
tongue  is  effected. 

The  tongue  is  a  double  organ,  composed  chiefly  of 
muscular  fibers,  which  run  in  almost  every  direction. 
The  two  sides  are  absolutely  distinct,  so  that  sometimes, 
as  in  paralysis,  one  side  is  affected  while  the  function  of 
the  other  remains  unimpaired.  It  possesses  great  versa- 
tility of  motion,  and  can  be  molded  into  a  variety  of  shapes. 
The  tongue  is  an  auxiliary  to  other  organs  in  articulation, 
mastication,  and  deglutition. 

This  organ  is  abundantly  supplied  with  blood-vessels, 
a  large  artery  being  sent  to  each  side  of  it.  It  is  also 
well  furnished  with  nerves,  receiving  nervous  filaments 
from  the  fifth,  ninth,  and  twelfth  pairs  of  nerves.  The 
branch  of  the  fifth,  formerly  called  the  gustatory,  from  its 


THE    ORGANS   OF  SPECIAL   SENSE 


265 


fancied  connection  with  the  sense  of  taste,  is  the  nerve  of 
common  sensation  for  the  tongue.     The  ninth  or  glosso- 


FlG.  140. — The  upper  surface  of  the  tongue,  with  the  fauces  and  tonsils  : 
I,  I,  Circumvallate  papillae,  in  front  of  2,  the  foramen  caecum  ;  3,  fungiform 
papillae  ;  4,  filiform  and  corneal  papillae  ;  5,  transverse  and  oblique  rugae  ;  6, 
mucous  glands  at  the  base  of  the  tongue  and  in  the  fauces  ;  7,  tonsils  ;  8, 
part  of  the  epiglottis;  9,  median  glosso-epiglottidean  fold  (frasnum  epi- 
glottidis)  (from  Sappey). 


pharyngeal  nerve  is  the  special  nerve  of  taste,  and  is  dis- 
tributed to  the  posterior  third  of  the  organ;  the  chorda 
tympani  supplies  the  anterior  two-thirds.     The  twelfth, 


266      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

or  hypoglossal  nerve,  is  the  motor  nerve  of  the  tongue. 
It  also  helps  to  bring  the  tongue,  fauces,  esophagus,  and 
larynx  together,  which  is  necessary  in  order  to  get  the  full 
effect  of  taste. 

The  mucous  membrane  covering  the  under  surface  of 
the  tongue  is  exactly  like  that  lining  the  remainder  of  the 
oral  cavity.  The  mucous  membrane  upon  the  dorsum  of 
the  tongue,  instead  of  being  thin  and  smooth,  is  thick  and 
rough  due  to  the  presence  of  papiJlcB.  These  structures 
are  papillary  projections  of  the  corium  and  are  of  three 
varieties.  The  largest  or  circumvallate  papilla,  from  eight 
to  ten  in  number,  form  an  inverted  V  at  the  back  of  the 
tongue  (Fig.  140).  The  fungiform  papillcB  are  found 
chiefly  at  the  tip  and  side  of  the  tongue.  The  filiform 
papillcB  are  distributed  over  the  anterior  two-thirds  of  the 
dorsum. 

THE   ORGANS   OF   SMELL 

The  sense  of  smell  is  located  in  the  mucous  membrane 
of  the  nose.  To  understand  fully  the  sense  of  smell,  a 
knowledge  of  the  structure  of  the  nasal  cavity  and  the 
distribution  of  the  olfactory  nerve  is  necessary. 

The  nose  is  composed  of  bones,  fibrocartilages,  mucous 
membrane,  and  an  outer  covering  of  integument.  The 
hones  that  make  up  the  nose  are  the  nasal  and  the  nasal 
processes  of  the  upper  jaw  (superior  maxillary).  The 
fibrocartilages  are  five  in  number,  and  give  form  and  stabil- 
ity by  their  elasticity  to  the  framework  of  the  nose,  at 
the  same  time  guarding  against  injury.  The  mucous 
membrane,  which  lines  the  interior  of  the  nose,  is  continuous 
with  the  skin  externally  and  with  the  lining  membrane 
of  the  nasal  fossae.  The  margins  of  the  nostrils  are  pro- 
vided with  numerous  hairs  that  serve  to  protect  the  deli- 
cate membrane  of  the  nose  against  the  entrance  of  irri- 
tating substances. 


THE    ORGANS   OF  SPECIAL   SENSE 


267 


The  nasal  fossae  are  two  irregular  cavities  extending 
upward  and  backward  from  the  nostrils  or  anterior  nares, 


Upper  lateral 
cartilage. 

Lower  lateral 
cartilage 


Sesamoid  bones. 
Cell-tissue. 


Fig.  141. — Lateral  cartilages  of  the  nose  (Ingals). 

terminating  in  the  pharynx  as  the  posterior  nares.     They 
are  bounded  superiorly  by  the  sphenoid  and  ethmoid 


Fig.  142. — Nerves  of  nose  and  sphenopalatine  ganglion,  from  inner  side: 
I,  Network,  of  external  branches  of  olfactory  nerve;  2,  nasal  nerve,  giving 
its  external  branch  to  outer  wall  of  nose ;  the  septal  branch  is  cut  short;  3, 
sphenopalatine  ganglion;  4,  ramification  of  large  palatine  nerve ;  5,  small, 
and  6,  external  palatine  nerve;  7,  inferior  nasal  branch;  8,  superior  nasal 
branch  ;  9,  nasopalatine  nerve  cut  short;  10,  Vidian  nerve;  11,  great  super- 
ficial petrosal  nerve;  12,  great  deep  petrosal  nerve;  13,  the  sympathetic 
nerves  ascending  on  internal  carotid  artery. 


bones;  inferiorly,  by  the  hard  palate.     In  the  middle  line 
they  are  separated  from  each  other  by  a  bony  and  fibro- 


268      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

cartilaginous  septum;  upon  the  outer  walls  of  each  fossa, 
in  the  dried  skull,  are  three  projecting  processes,  termed 
spongy  or  turbinated  hones.  In  the  fresh  fossa  these  are 
covered  by  a  mucous  membrane. 

The  space  that  intervenes  between  the  superior  and 
middle  spongy  bones  is  termed  the  superior  meatus,  or 
channel ;  the  space  between  the  middle  and  inferior  bones, 
the  middle  meatus;  and  that  between  the  inferior  bone  and 
the  floor  of  the  fossa,  the  inferior  meatus.  The  meatuses 
are  passages  that  extend  backward  from  the  nostrils; 
they  contain  several  openings.  They  are  lined  by  a 
mucous  membrane,  called  the  pituitary,  or  Schneiderian 
membrane  (from  Schneider,  who  first  showed  that  the 
secretion  of  the  nasal  fossae  proceeded  from  the  mucous 
membrane,  and  not  from  the  brain,  as  was  formerly 
taught) . 

Upon  the  mucous  membrane  of  the  nasal  passage  the 
olfactory  nerve  and  also  branches  from  other  nerves 
ramify.  This  membrane  is  quite  extensive  in  man,  and  is 
even  more  so  in  those  animals  whose  sense  of  smell  is 
very  acute. 

THE   ORGANS   OF   TOUCH 

The  sense  of  touch  or  palpable  feeling  is  the  one  by 
which  the  mind  becomes  acquainted  with  some  of  the 
properties  of  bodies;  thus,  it  enables  us  to  determine 
whether  their  surfaces  are  smooth  or  rough,  their  relative 
temperature,  and,  to  a  certain  degree,  also  their  form  and 
weight.  The  skin,  which  is  the  principal  seat  of  the 
sense  of  touch,  has  been  described  in  a  previous  chapter. 

Some  physiologists  make  a  distinction  between  the 
sense  of  touch  and  of  tact.  Tact,  or  feeling,  is  a  more  gen- 
eral faculty,  extending  over  the  whole  surface  of  the  skin 
and  mucous  membranes,  whereas  touch  is  confined  chiefly 
to  the  fingers  of  man  and  the  noses  of  quadrupeds.     Tact 


THE    ORGANS   OF  SPECIAL   SENSE  269 

is  considered  a  passive  function;  for  example,  when  any 
part  of  the  system  comes  into  contact  with  another  body, 
a  sensation  of  its  presence  is  given  without  the  exercise  of 
voHtion.  On  the  other  hand,  touch  is  an  active  sense, 
and  is  exercised  voluntarily,  for  the  purpose  of  conveying 
to  the  mind  a  knowledge  of  the  qualities  or  properties  of 
the  surfaces  of  bodies;  as,  for  example,  when  we  feel  a 
piece  of  cloth  to  ascertain  its  quality,  or  a  polished  surface 
to  prove  its  smoothness. 

In  man  the  hand  is  admirably  adapted  for  the  exercise 
of  the  sense  of  touch.  The  fineness  of  the  skin,  its  great 
sensibility,  the  cushion-Uke  pad  formed  by  the  subcutane- 
ous fat  at  the  extremities  of  the  fingers,  the  length  and 
flexibility  of  these  members,  and  the  power  we  possess  of 
opposing  the  thumb  to  the  fingers,  thus  forming,  as  it 
were,  a  pair  of  forceps,  are  properties  that  are  essential 
to  the  delicacy  of  touch,  and  that  enable  us  to  appreciate 
with  exactitude  the  qualities  of  the  bodies  we  may  feel. 

REVIEW    QUESTIONS 

What  constitute  the  organs  of  sight? 

How  many  coats  has  the  eye?     Name  them. 

What  is  the  conjunctiva? 

What  is  the  sclerotic  coat? 

Give  a  description  of  the  cornea. 

What  is  the  choroid  coat? 

What  is  the  iris? 

Give  an  illustration  of  the  ciliary  processes. 

What  and  where  is  the  retina? 

What  nerve  pierces  the  eyeball  posteriorly? 

Name  the  different  humors  of  the  eye. 

What  is  their  function? 

What  are  the  appendages  of  the  eye? 

What  are  the  functions  of  the  eyebrows? 

What  is  the  function  of  the  eyelids? 

What  do  you  understand  by  canthus? 

What  denotes  the  entrance  to  the  lacrimal  canal? 

What  is  the  function  of  the  tarsal  cartilages? 


270      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

What  is  the  function  of  the  Meibomian  glands? 
What  is  the  caruncula  lacrimaHs? 
Describe  the  nasal  duct. 

What  condition  is  liable  to  ensue  from  obstruction  of  this  duct? 
What  are  the  organs  of  hearing? 
How  is  the  sound  conveyed? 
How  is  the  ear  divided? 
What  composes  the  external  ear? 
What  is  the  construction  of  the  meatus  auditorius? 
Describe  the  membrana  tympani. 
What  is  the  tympanum? 

What  are  the  mastoid  cells?     Where  are  they  located? 
What  is  the  function  of  the  Eustachian  tubes? 
'Describe  the  internal  ear. 
What  are  the  organs  of  taste? 
What  are  papillae? 

Name  the  varieties  and  their  situation. 
How  are  the  papillae  on  the  dorsum  of  the  tongue  classiiBed? 
What  is  considered  the  nerve  of  taste? 
What  are  the  organs  of  the  sense  of  smell? 
Of  what  is  their  structure  composed? 

How  many  fibrocartilages  enter  into  the  formation  of  the  nose? 
What  cavities  are  formed  by  these  structures? 
Where  is  the  septum  located? 
What  nerve  supplies  the  sense  of  smell? 
What  do  you  mean  by  the  sense  of  touch? 
What  nerve  structures  enter  into  this  function? 
What  is  the  difference  between  tact  and  touch? 
Where  is  the  sense  of  touch  situated  in  animals? 


CHAPTER    XI 

THE  FEMALE  ORGANS  OF  GENERATION 

Thk  external  organs  of  generation  in  the  female 
are  the  mons  veneris,  labia  majora,  labia  minora,  clitoris, 


Fig.  143. — Virginal  vulva :  i,  Labia  majora ;  2,  fourchet ;  3,  labia  minora ; 
4,  glans  clitoridis;  5,  meatus  urinarius ;  6,  vestibule;  7,  entrance  to  the 
vagina;  8,  hymen;  9,  orifice  of  Bartholin's  gland;  10,  anterior  commissure 
of  labia  majora;  11,  anus;  12,  blind  recess;  13,  fossa  navicularis ;  14,  body 
of  clitoris  (modified  from  Tarnier). 

jneatus  urinarius,  and  the  orifice  of  the  vagina.  The 
term  vulva  or  pudendum,  as"  generally  applied,  includes  aU 
these  parts. 

271 


2/2      ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

The  mons  veneris  is  the  rounded  eminence  situated  in 
front  of  the  pubes;  it  is  formed  by  an  accumulation  of 
fatty  tissue  beneath  the  integument.  It  surmounts  the 
vulva,  and  at  puberty  becomes  covered  with  hair. 

The  labia  majora  are  two  prominent  longitudinal  cuta- 
neous folds,  extending  downward  from  the  mons  veneris 
to  the  anterior  boundary  of  the  perineum,  and  enclosing 
an  elliptic  fissure,  the  urinosexual  opening.    The  outer 


Fig.  144. — Normal  vulvovaginal  gland.  The  labium  majus  and  minus, 
the  sphincter  vaginae  muscle,  and  the  bulb  have  been  partly  removed  on  the 
right  side  in  order  to  expose  the  gland  :  AA' ,  Section  of  labium  majus  and 
minus;  ^,  gland ;  C,  excretory  duct ;  C,  stylet  introduced  into  the  duct; 
D,  glandular  end  of  duct ;  E,  free  end  of  duct ;  F,  section  of  bulb ;  G,  as- 
cending ramus  of  ischium  (Huguier). 


surfaces  of  the  labia  majora  are  covered  with  hair;  the 
inner  surfaces  are  continuous  with  those  of  the  genito- 
urinary mucous  tract. 

The  labia  minora  are  two  small  cutaneous  folds  situ- 
ated within  the  labia  majora,  and  extending  from  the  cli- 
toris obliquely  downward  and  outward  for  about  \\  inches 
on  each  side  of  the  orifice  of  the  vagina,  at  the  sides  of 
which  they  are  obliterated.     They  are  continuous  exter- 


THE  FEMALE    ORGANS   OF  GENERATION       273 

nally  with   the   labia  majora,   and  internally  with   the 
vagina. 

The  clitoris  is  an  erectile  structure,  situated  beneath 
the  anterior  commissure,  and  partially  hidden  between  the 
anterior  extremities  of  the  labia  minora. 


Fig.  145, — Sagittal  section  of  the  female  pelvis  (Dickinson). 


The  hymen  is  a  thin,  semilunar  fold  of  mucous  mem- 
brane, stretched  across  the  lower  part  of  the  orifice  of  the 
vagina;  its  concave  margin  turns  upward  toward  the 
pubes.  Occasionally  this  membrane  forms  a  complete 
septum  across  the  orifice  of  the  vagina,  forming  the  con- 

18 


2/4      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

dition  known  as  imperforate  hymen.  At  times  it  is 
cribriform,  or  it  may  be  entirely  absent.  The  presence  of 
the  hymen  cannot,  consequently,  be  considered  as  an 
absolute  test  of  virginity.  Its  rupture,  or  a  rudimentary 
condition  of  this  membrane,  gives  rise  to  irregular  eleva- 
tions that  surround  the  opening  of  the  vagina. 

The  Glands  of  Bartholin. — These  are  situated  one  on 
each  side  of  the  commencement  of  the  vagina.  They 
are  round  or  oblong  bodies,  of  a  reddish-yellow  color,  and 
the  size  of  a  bean;  each  gland  opens  by  means  of  a  long 
single  duct,  upon  the  inner  side  of  the  nymphae,  external 
to  the  hymen. 

The  bladder,  because  of  its  proximity  to  the  organs  of 
generation,  is  mentioned  here.  It  is  situated  at  the 
anterior  part  of  the  pelvis,  and  is  in  relation,  in  front,  with 
the  OS  pubis;  behind,  with  the  uterus,  some  convolutions 
of  the  small  intestine  being  interposed;  its  base  lies  in 
contact  with  the  neck  of  the  uterus  and  with  the  anterior 
wall  of  the  vagina.  The  bladder  is  larger  in  the  female 
than  in  the  male,  and  it  is  very  broad  in  its  transverse 
diameter.  A  more  exhaustive  description  of  this  organ 
has  been  given  in  a  previous  chapter. 

THE   VAGINA 

The  vagina  is  a  membranous  canal  extending  from  the 
vulva  to  the  uterus.  It  is  situated  in  the  cavity  of  the 
pelvis,  behind  the  bladder,  and  in  front  of  the  rectum. 
In  direction  it  is  curved  forward  and  downward,  following, 
at  first,  the  line  of  the  axis  of  the  cavity  of  the  pelvis,  and 
afterward  that  of  the  outlet.  It  is  cylindric  in  shape, 
flattened  from  before  backward,  and  its  walls  are  ordina- 
rily in  contact  with  each  other.  Its  length  is  about  4 
inches  along  its  anterior  wall.  At  its  commencement  it 
is  constricted,  becoming  dilated  near  the  uterine  extremity. 
It  surrounds  the  cervical  portion  of  the  cervix  uteri,  a 


THE  FEMALE    ORGANS   OF  GENERATION       275 

short  distance  from  the  os,  and  its  attachment  extends 
higher  up  on  the  posterior  than  on  the  anterior  wall.     The 


Fig.  146. — ^View  of  the  pelvis  and  its  organs :  B,  Bladder ;  U,  uterus 
(drawn  down  by  loop  e) ;  F,  Fallopian  tubes ;  O,  ovaries ;  L,  round  liga- 
ments; g,  ureter;  a,  ovarian  vessels,  often  prominent  under  their  peritoneal 
covering  (Savage). 

vagina  consists  of  a  muscular  coat,  a  layer  of  erectile 
tissue,  and  an  internal  mucous  lining. 


THE  UTERUS 

The  uterus  is  the  organ  of  gestation,  receiving  the 
fecundated  ovum  in  its  cavity,  retaining  and  supporting 
it  during  the  development  of  the  fetus,  and  becoming  the 
principal  agent  in  its  expulsion  at  the  time  of  parturition. 

In  the  virgin  state  it  is  pear-shaped,  flattened  from 
before  backward,  and  situated  in  the  cavity  of  the  pelvis, 
between  the  bladder  and  the  rectum;  it  is  retained  in 
position  by  the  round  and  broad  ligaments  on  each  side, 


2/6      ANATOMY  AND  PHYSIOLOGY  FOR   NURSES 

and  projects  into  the  upper  end  of  the  vagina  below.  The 
base  projects  upward  and  the  cervix  downward,  in  the 
Hne  of  the  axis  of  the  inlet  of  the  pelvis.  The  uterus 
measures  about  3  inches  in  length,  2  in  breadth  at  its  upper 
part,  and  i  inch  in  thickness;  it  weighs  from  i  to  i| 
ounces.  For  descriptive  purposes  it  is  divided  into  three 
parts — the  cervix,  the  body,  and  the  fundus.  The 
fundus  is  the  upper  broad  extremity  of  the  organ;  the 
body  gradually  extends  toward  the  cervix,  which  is  the 


Tube. 

Round 
ligament. 


Reflection  of 
peritoneum. 


Fig.  147. — Anterior  view  of  virgin  uterus,  showing  relations  of  cervix  to 
corpus  uteri  and  relation  of  peritoneum  at  isthmus  ( The  American  Text- 
book of  Obstetrics^ . 

lower  part,  and  is  divided  into  two  sections — the  supra- 
vaginal portion  above  and  the  vaginal  portion  below. 
The  vaginal  cervix  is  consequently  that  part  of  the  cervix 
which  projects  into  the  vagina. 

Structure. — The  uterus  is  composed  of  three  coats 
— the  external  serous  coat,  a  middle  or  muscular  layer, 
and  an  internal  mucous  coat;  the  muscular  coat  forms 
the  greater  bulk  of  the  organ.  In  an  unimpregnated 
state  it  is  firm,  of  a  grayish  color,  and  cuts  almost  like 


THE  FEMALE    ORGANS   OF  GENERATION       2/7 

cartilage.  It  is  classed  as  an  involuntary  muscle,  and  in 
the  impregnated  state  the  muscular  tissue  becomes  more 
prominently  developed. 

Blood=supply. — The  uterus  is  supplied  with  blood 
from  the  internal  iliac  through  the  uterine  artery,  and 
from  the  ovarian  from  the  aorta. 

The  nerves  are  derived  from  the  inferior  hypogastric 
and  spermatic  plexuses,  and  from  the  third  and  fourth 
sacral  nerves. 

The  form,  size,  and  situation  of  the  uterus  varies  at 
different  periods  of  life  and  under  different  conditions. 

In  the  jetus  the  uterus  is  contained  in  the  abdominal 
cavity,  projecting  beyond  the  brim  of  the  pelvis.  The 
cervix  is  considerably  larger  than  the  body. 

At  puberty  the  uterus  is  pyriform  in  shape,  and  weighs 
from  8  to  lo  drams.  It  has  descended  into  the  pelvis,  the 
fundus  being  just  below  the  level  of  the  brim  of  this  cavity. 

During  and  after  menstruation  this  organ  is  enlarged, 
more  vascular,  and  its  surface  rounder;  the  external  os  is 
rounded,  its  lips  are  swollen,  and  the  lining  membrane  of 
the  body  is  thickened,  softer,  and  of  a  darker  color. 

During  pregnancy  the  uterus  increases  in  weight  from 
i^  to  3  pounds.  It  becomes  enormously  enlarged,  and 
projects  into  the  hypogastric  and  lower  part  of  the  umbili- 
cal region.  The  enlargement,  which  continues  up  to  the 
sixth  month  of  gestation,  is  due  partly  to  increased  de- 
velopment of  pre-existing  and  newly  formed  muscular 
tissue.  The  round  ligaments  are  enlarged,  and  the  broad 
ligaments  become  encroached  upon  by  the  uterus  making 
its  way  between  the  laminae.  The  mucous  membrane 
becomes  more  vascular,  and  its  mucous  follicles  and 
glands  enlarge;  the  rugae  and  folds  of  the  cervix  become 
obliterated;  the  blood-vessels  and  lymphatics,  as  well  as 
the  nerves,  become  greatly  enlarged. 

After  parturition  the  uterus  almost  regains  its  usual 


2^8      ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

size;  its  weight  now  is  from  2  to  3  ounces,  but  its  cavity 
is  larger  than  in  the  virgin  state;  the  external  orifice  is 
more  marked,  and  assumes  a  transverse  direction;  its 
edges  present  a  fissured  surface;  its  vessels  are  tortuous 
and  its  muscular  layers  are  more  clearly  defined. 

In  old  age  the  uterus  becomes  atrophied,  paler,  and 
denser  in  texture,  and  a  more  distinct  constriction  separates 
the  body  and  cervix.     The  internal  os  and,  occasionally, 


Fig.  148. — Longitudinal  section  of  a  nulliparous  (A)  and  of  a  multipar- 
ous  (B)  uterus:  A,  Cavity  of  the  cervix  and  arbor  vitae;  C,  cavity  of  the 
body  ;  O,  constriction  between  body  and  cervix,  the  internal  os ;  S,  wall  of 
body  (Tarnier). 


the  vaginal  orifice  often  become  obliterated,  and  its  lips 
almost  entirely  disappear. 

The  cavity  of  the  uterus  continues  to  the  fundus.  It 
is  of  an  irregular  size,  a  constriction  at  the  cervical  por- 
tion forming  the  internal  os,  and  the  part  within  the 
vagina  the  external  os.  The  cavity  is  continuous  with 
that  of  the  Fallopian  tubes. 

The  ligaments  are  six  in  number — two  posterior,  two 
anterior,  and  two  lateral  or  broad  ligaments.  These  are 
all  formed  of  peritoneum. 


THE   FEMALE    ORGANS   OF  GENERATION        2/9 
APPENDAGES   OF   THE   UTERUS 

The  appendages  of  the  uterus  are  the  Fallopian  tubes, 
the  ovaries  and  their  ligaments,  and  the  round  ligaments. 
These  structures,  together  with  their  nutrient  vessels  and 
nerves  and  some  scattered  muscular  fibers,  are  enclosed 
between  the  two  folds  of  peritoneum  which  constitute  the 
broad  ligaments.  They  are  placed  in  the  following  order: 
in  front  is  the  round  ligament ;  the  Fallopian  tube  occupies 


Fig.  149. — Posterior  view  of  left  uterine  appendages:  i,  Uterus;  2, 
Fallopian  tubes;  3,  fimbriated  extremity  and  opening  of  the  Fallopian  tube; 
4,  parovarium  ;  5,  ovary ;  6,  broad  ligament ;  7,  ovarian  ligament ;  8,  infundi- 
bulopelvic  ligament  (Henle). 

the  free  margin  of  the  broad  ligament;  the  ovary  and  its 
ligament  are  behind  the  latter. 

The  Fallopian  tubes,  or  oviducts,  convey  the  ova 
from  the  ovaries  to  the  cavity  of  the  uterus.  They  are 
two  in  number,  one  on  each  side,  situated  in  the  free  mar- 
gin of  the  broad  ligament,  extending  from  each  superior 
angle  of  the  uterus  to  the  side  of  the  pelvis.  Bach  tube  is 
about  4  inches  in  length ;  its  canal  is  exceedingly  small,  and 
commences  at  the  superior  angle  of  the  uterus  by  a  minute 


2So      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

orifice,  the  ostium  internum;  this  will  hardly  admit  a 
fine  bristle ;  it  continues  narrow  along  the  inner  half  of  the 
tube,  and  then  gradually  widens  into  a  trumpet-shaped  ex- 
tremity that  becomes  contracted  at  its  termination.  This 
orifice  is  called  the  ostium  abdominale,  and  communicates 
with  the  peritoneal  cavity.  Its  margins  are  surrounded 
by  a  series  of  fringe-like  processes,  termed  fimbrincB;  one 
of  these  processes  is  connected  with  the  outer  end  of  the 
ovary.     The  name  fimbriated  extremity  is  applied  to  this 


Fig.  150. — Transverse  section  of  the  human  Fallopian  tube  (Schenck). 

part  of  the  tube;  owing  to  the  peculiar  manner  in  which  it 
embraces  the  surface  of  the  ovary  during  sexual  excite- 
ment it  is  also  called  morsus  diaboli. 

The  Fallopian  tubes  consist  of  three  coats — serous, 
muscular,  and  mucous. 

The  Ovaries. — ^The  ovaries  are  oval  bodies,  of  an 
elongated  form,  flattened  from  above  downward,  and 
situated  one  on  each  side  of  the  uterus  in  the  posterior 
part  of  the  broad  ligament,  behind  and  below  the  Fallopian 
tubes.     Bach  ovary  is  connected,  by  its  anterior  margin, 


THE   FEMALE    ORGANS   OF  GENERATION       28 1 

with  the  broad  ligament;  by  its  inner  extremity,  to  the 
uterus  by  a  proper  Hgament — the  Hgament  of  the  ovary; 
and  by  its  outer  end,  to  the  fimbriated  extremity  of  the 
Fallopian  tube  by  a  short  ligamentous  cord. 

The  ovaries  are  of  whitish  color,  and  present  either  a 
smooth  or  a  puckered,  uneven  surface.  They  are  each 
about  \\  inches  in  length,  f  inch  in  width,  and  about 
\  inch  thick;  they  weigh  from  i  to  2  drams.  They 
are  attached  to  the  broad  ligament,  and  are  invested  by 


Fig.  151. — Ovary  and  tube  of  woman  twenty-four  years  old,  seen  from 
behind:  U,  Uterus;  T,  tube;  LO,  ovarian  ligament;  0,  ovary;  x,  limit  of 
peritoneum ;  b,  cicatrix  after  ruptured  Graafian  follicle  (Waldeyer). 


peritoneum  excepting  along  the  anterior  margin,  where 
they  are  attached.  The  ovaries  contain  numerous 
small,  round,  transparent  vesicles  in  various  stages  of 
development;  these  are  called  the  Graafian  vesicles,  the 
ovisacs  containing  the  ova.  In  women  who  have  not 
borne  children  they  vary  in  number  from  ten  to  fifteen  or 
twenty,  and  in  size  from  a  pin's  head  to  a  pea.  It  has' 
been  shown  that  a  large  number  of  ovisacs  exist  in  the 
parenchyma  of  the  ovary,  few  of  which  produce  ova. 


282      ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

These  vesicles  have  thin,  transparent  walls,  and  are  filled 
with  a  clear,  colorless,  albuminous  fluid.  The  Graafian 
vesicles  are,  during  their  early  development,  small,  and 


Fig.  152. — Section  through  part  of  ovary  of  adult  bitch:  <z,  Germinal 
epithelium;  b,  b,  ingrowths  (egg-tubes)  from  the  germinal  epithelium,  seen 
in  cross-section  ;  c,  c,  young  Graafian  follicles  in  the  cortical  layer ;  d,  a 
more  mature  follicle,  containing  two  ova  (this  is  rare)  ;  e  and  f,  ova  sur- 
rounded by  cells  of  discus  proligerus  ;  g,  h,  outer  and  inner  capsules  of  the 
follicle ;  i,  membrana  granulosa ;  /,  blood-vessels ;  m,  m,  parovarium  ;  g, 
germinal  epithelium  commencing  to  grow  in  and  form  an  egg-tube  ;  z,  tran- 
sition from  peritoneal  to  germinal  epitheUum  (from  Waldeyer). 

deeply  seated  in  the  substance  of  the  ovary;  as  they 
enlarge  they  approach  the  surface,  and  when  mature 
they  form  smaU  projections  on  the  exterior  of  the  ovary 


THE  FEMALE    ORGANS   OF  GENERATION       283 

beneath  the  peritoneum.  Each  vesicle  consists  of  an 
external  fibrovascular  coat,  connected  with  the  sur- 
rounding stroma  of  the  ovary  by  a  network  of  blood-ves- 
sels. 

The  ovum  is  an  extremely  minute,  spheric  body,  meas- 
uring from  2^^o  to  xio  inch  in  diameter. 


Fig.  153.— Graafian  follicle  from  a  girl  seven  months  old  :  a,  Epithelium 
(membrana  granulosa)  detached  from  fibrous  membrane ;  b,  discus  pro- 
ligerus,  situated  far  away  from  the  surface.  It  contains  the  ovum,  on  vi^hich 
the  zona  pellucida  and  the  germinal  vesicle  are  visible.  The  surrounding 
fibrous  membrane  is  not  yet  separated  into  two  layers,  and  there  is  no  dis- 
tinct line  of  demarcation  between  it  and  the  surrounding  stroma  (X  220 
times ;  natural  size,  0.351  mm.  longest  diameter)  (KoUiker). 


Discharge  of  the  Ovum. — The  Graafian  vesicles,  after 
gradually  approaching  the  surface  of  the  ovary,  burst; 
the  ovum  and  fluid  contents  of  the  vesicle  are  liberated 
and  escape  on  the  exterior  of  the  ovary,  passing  thence 
into  the  Fallopian  tube,  the  fimbriated  processes  of 
which  are  thought  to  grasp  the  ovary,  the  aperture  of  the 
tube  being  applied  to  the  part  corresponding  to  the 
matured  and  bursting  vesicle. 


2^4      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

The  maturation  and  discharge  of  the  ova  occur  at  regu- 
lar periods  only ;  these  periods  are  known  as  the  menstrual 
periods.  Sexual  desire  is  more  intense  in  females  at  this 
time,  and  if  union  of  the  sexes  takes  place,  the  ovum  may 
become  fecundated.     (8^e  page  291.) 

The  Corpus  Luteum.-  -Immediately  after  the  rupture  of 
the  Graafian  vesicle  ami  the  escape  of  its  ovum  the 
vesicle  becomes  filli^d  with  blood-stained  fluid,  and  in  a 
short  time  the  circumference  of  the  vesicle  is  occupied 
by  a  firm,  yellow  substance  that  is  probably  formed  from 
plasma  exuded  from  its  walls.    Tl  e  exudation  is  at  first  of 


Fig.  154. — Ovary  with  mature  Graafian  follicle  about  ready  to  burst  (Ribe- 
mont-Dessaignes). 


a  dark  brown  or  brownish-red  color,  but  it  soon  becomes 
paler  and  its  consistence  denser. 

For  every  follicle  in  the  ovary  from  which  an  ovum  is 
discharged  a  corpus  luteum  will  be  found,  but  the  charac- 
ter it  exhibits  and  the  changes  produced  in  it  will  be  de- 
termined by  the  circumstances  of  the  ovum  being  impreg- 
nated or  not. 

Ligaments  of  the  Ovaries. — The  ligaments  of  the 
ovaries  are  rounded  cords  that  extend  from  each  superior 
angle  of  the  uterus  to  the  inner  extremity  of  the  ovary. 
They  consist  of  fibrous  tissue  and  a  few  fibers  derived  from 
the  uterus. 


THE   FEMALE    ORGANS   OF  GENERATION 


285 


The  round  ligaments  are  two  rounded  cords,  between 
4  and  5  inches  in  length,  situated  between  the  layers  of 
the  broad  ligaments,  in  front  of  and  below  the  Fallopian 
tubes.  Commencing  on  each  siue  at  the  superior  angle 
of  the  uterus,  each  ligament  passes  forward  and  outward 
through  the  internal  abdominal  /ing,  along  the  inguinal 
canal,  to  the  labia  majora,  in  whi-^h  it  becomes  obliterated. 

Blood-supply  of  the  Ovaries. — The  u/teries  of  the  ovaries 
and  Fallopian  tubes  are  the  ovarian,  from  the  aorta,  anas- 


FlG.  155. — Stages  in  the  formation  of  a  corpus  luteum :  A,  Recent  blood; 
£,  the  wrinkhng  of  its  walls ;  C,  contracting  stage  (A.  E.  Giles). 


tomosing  with  the  termination  of  the  uterine  arteries,  and 
entering  the  attached  border  of  the  ovary.  The  veins 
follow  the  course  of  the  arteries;  they  form  a  plexus  near 
the  ovary — the  pampiniform  plexus. 

The  nerves  are  derived  from  the  spermatic  plexus, 
the  Fallopian  tube  receiving  a  branch  from  one  of  the 
uterine  nerves. 


REVIEW    QUESTIONS 


What  are  the  female  organs  of  generation? 
What  is  the  mons  veneris? 


286     ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

What  are  the  labia  majora?    The  labia  minora? 
AVhat  is  the  clitoris?    The  hymen? 
What  are  the  glands  of  Bartholin? 
Describe  the  vagina. 
What  are  the  functions  of  the  uterus? 
What  arteries  supply  the  uterus? 

State  the  changes  that  take  place  in  the  uterus  at  different  periods 
of  life. 

What  are  the  appendages  of  the  uterus? 

What  are  the  Fallopian  tubes? 

How  many  are  there? 

What  ligaments  hold  them  in  position? 

What  is  the  function  of  the  Fallopian  tubes? 

What  do  you  understand  by  the  fimbriated  processes? 

What  are  the  ovaries? 

Where  are  they  located? 

What  is  a  Graafian  vesicle? 

Describe  an  ovum. 

What  is  the  corpus  luteum? 

Describe  the  ligaments  of  the  ovaries. 

What  arteries  supply  the  ovaries? 


CHAPTER    XII 
THE  MALE  ORGANS  OF  GENERATION 

The;  male  organs  of  generation  include  the  prostate 
gland,  the  penis  and  the  testicles,  with  their  appendages, 
and  the  seminal  vesicles. 

The  Prostate  Gland. — The  prostate  gland  surrounds 
the  commencement  of  the  urethra,  lying  in  the  pelvic 
cavity  behind  and  below  the  symphysis  pubis  and  in  front 
of  the  rectum.  It  is  shaped  like  a  horse-chestnut,  measur- 
ing 1 1  inches  transversely,  i  inch  from  before  backward, 
and  f  inch  in  depth.  It  is  composed  of  numerous 
pouched  glands  embedded  in  interlacing  bundles  of  mus- 
cular tissue,  the  whole  being  enclosed  in  a  fibrous  capsule 
(Fig.  156,  i). 

The  prostate  gland  surrounds  the  prostatic  portion  of  the 
urethra,  which  is  i  J  inches  long.  The  floor  of  the  prostatic 
urethra  contains  a  longitudinal  ridge,  called  the  verumon- 
tanum  or  caput  gallinaginis,  on  either  side  of  which  is  a 
slight  fossa  known  as  the  prostatic  sinus.  In  front  of  the 
verumontanum  is  a  depression,  the  sinus  pocularis  or 
uterus  masculinus,  upon  the  margin  of  which  are  the  ori- 
fices of  the  ejaculatory  ducts. 

Cowper's  glands  are  two  small,  rounded,  yellowish 
bodies,  about  the  size  of  peas,  situated  behind  the  begin- 
ning of  the  membranous  portion  of  the  urethra.  They 
open  by  means  of  ducts  on  the  floor  of  the  urethra.  (See 
Figs.  156,  h,  and  157,  6.) 

The  penis  serves  the  double  purpose  as  the  termination 

287 


288      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

of  the  urinary  passages  and  as  the  organ  of  sexual  inter- 
course. This  organ  consists  of  erectile  tissue  arranged 
in  three  subdivisions,  two  above,  corpora  cavernosa,  and 
one  below,  corpus  spongiosum,  which  latter  surrounds 
the  spongy  portion  of  the  urethra  and  terminates  in  the 
glans  penis.  The  glans  penis  is  covered  with  a  loose  fold 
of  skin,  the  foreskin  or  prepuce.  The  corpora  cavernosa 
are  surrounded  by  fibro-elastic  sheaths  from  which  are 
given  off  trabeculae.  Between  these  trabeculae  are  spaces 
which  contain  venous  blood.     A  similar  structure  char- 


FlG.  156. — A  vertical  section  of  the  bladder,  penis,  and  urethra :  a,  Glans 
penis;  b,  c,  corpus  cavernosum ;  d,  fossa  navicularis ;  e,  corpus  spongiosum; 
/,  spongy  portion  of  urethra ;  ^,  bulb  of  the  corpus  spongiosum ;  h,  Cow- 
per's  glands;  i,  the  prostate;  k,  vas  deferens;  /,  seminal  vesicles;  m,  pros- 
tatic portion  of  urethra;  0,  bladder;  /,  pubic  bone;  r,  commencement  of 
urethra;  s,  membranous  urethra. 


acterizes  the  corpus  spongiosum,  which  encloses  the 
urethra.     This  structure  is  known  as  erectile  tissue. 

The  male  urethra  is  described  on  page  187. 

Testes. — The  testes  or  testicles  are  the  male  pro- 
creating glands,  which  secrete  the  spermatozoa.  They 
are  two  in  number,  of  ovoid  form,  and  are  each  suspended 
in  the  scrotum  by  the  spermatic  cord.  They  measure  i\ 
inches  in  length,  i  inch  in  breadth,  and  i\  inches  from 
before  backward.  They  weigh  from  6  to  8  drams  each, 
the  left  being  slightly  the  larger. 

The  testes  are  composed  of  lobules,  the  number  of  which 


THE   MALE    ORGANS   OF  GENERATION 


289 


in  each  organ  varies  from  two  hundred  and  fifty  to  four 
hundred.  In  each  lobule  are  convoluted  seminiferous 
tubules,  varying  in  number  from  one  to  three.  The  coats 
of  the  testes  are :  the  tunica  vaginalis  externus,  an  external 
coat  derived  from  the  peritoneum;  the  tunica  albuginea, 
formed  of  white,  fibrous  tissue,  surrounding  the  gland  and 
reflected  into  its  interior  to  form  an  incomplete  partition 
from  which  septa  are  given  off,  separating  the  gland  into 


Fig.  157. — Diagram  representing  the  male  genital  apparatus  of  right 
side:  A,  bladder;  B,  prostatic  urethra;  C,  membranous  urethra;  D, 
spongy  urethra;  i,  Right  testicle;  2,  epididymis;  3,  vas  deferens,  with  3, 
its  ampulla;  4,  seminal  vesicle  ;  5,  ejaculatory  duct  opening  at  the  verumon- 
tanum  ;  6,  Cowper's  gland  ;  7,  its  excretory  duct  (Testut). 


lobes ;  the  tunica  vasculosa,  or  pia  mater  testis,  consisting  of 
a  plexus  of  blood-vessels  covering  the  inner  surface  of  the 
tunica  albuginea. 

The  epididymis  is  a  convoluted  tube,  some  20  feet  long, 
lying  along  the  posterior  border  of  the  testes,  being 
formed  by  a  convergence  of  the  efferent  vessels  of  the 
seminiferous  tubules  of  the  testes,  and  terminating  in  the 
vas  deferens  or  excretory  duct  of  the  testes.     This  duct, 

19 


290      ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

together  with  arteries  and  nerves  from  the  testes,  all 
bound  together  with  connective  tissue,  forms  the  spermatic 
cord.  The  vas  deferens  passes  upward  from  the  testes 
through  the  inguinal  ring  and  canal,  then  down  into  the 
pelvis  and  under  the  bladder,  running  forward  to  enter  the 
prostatic  urethra. 

The  scrotum  is  a  pouch  of  skin  and  fascia  suspended  from 
the  perineum  and  containing  the  testicles. 


G\ol)o$  Nil 


Fig.  158.— Vertical  section  of  the  testicle  to  show  the  arrangement  of  the 
ducts  (Leroy). 


Seminal  Vesicles. — These  are  two  lobulated  recep- 
tacles for  the  semen  which  they  dilute  with  their  own  secre- 
tion. They  lie  in  contact  with  the  base  of  the  bladder 
(Figs.  159  and  160),  diverging  from  each  other  from  the 
base  of  the  prostate  to  near  the  entrance  of  the  ureters. 
They  join  by  their  anterior  pointed  extremities  with  the 


THE   MALE    ORGANS   OF  GENERATION 


291 


vas  deferens,  forming  on  each  side  the  ejaculatory  duct, 
which  opens  into  the  prostatic  urethra. 

Semen. — The  semen,  or  seminal  fluid,  consists  of  secre- 
tions from  the  testes,  seminal  vesicles,  prostate,  and  other 
glands  connected  with  the  male  genital  tract.  The  es- 
sential elements  are  the  spermatozoa,  or  male  reproductive 


Fig.  159. — Seminal  vesicles  and  vasa  deferentia,  posterior  view :  i, 
Bladder;  2,  prostate;  3,  3',  seminal  vesicles;  4,  4',  vasa  deferentia;  5,  ejacu- 
latory ducts  ;  6,  6',  ureters  ;  7,  7,  perivesicular  cul-de-sac  of  peritoneum  ;  8, 
interdeferential  triangle,  in  direct  relation  with  the  rectum,  from  which  it  is 
separated  only  by  the  prostatoperitoneal  aponeurosis.  The  two  crosses 
(-[-  -h)  indicate  the  points  at  which  the  ureters  disappear  in  the  vesical  wall 
(Testut). 


cells  (Fig.  161),  which  are  secreted  by  the  testes.  The 
spermatozoa  are  about  50  fi  in  length  and  consist  of  a 
body  and  tail,  the  latter  serving  to  give  to  the  cell  the 
power  of  moving  about. 

Impregnation. — The  function  of  the  spermatozoon 
is  to  produce  impregnation  or  fertilization  of  the  ovum. 
To  accomplish  this  it  must  come  in  contact  with  the 


292      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

ovum  in  the  uterus  or  Fallopian  tube  of  the  female. 
The  head  of  the  spermatozoon  enters  the  ovum,  and  there 


Fig.  160. — Vas  deferens  and 
seminal  vesicle,  A,  seen  in  longi- 
tudinal, and  B,  in  horizontal,  sec- 
tion :  I,  Vas  deferens;  2,  its  ter- 
minal or  ampullary  portion ;  3, 
seminal  vesicle  with  (3')  its  parti- 
tions ;  4,  its  terminal  portion ;  5, 
ejaculatory  duct  (Testut). 


m: 


.^d 


Fig.  161. — Human  spermatozoa, 
greatly  magnified,  the  one  at  the 
extreme  left  is  seen  in  profile ;  the 
others  in  surface  view ;  the  one  at 
the  right  is  drawn  as  described  by 
Jensen  :  a.  Head  ;  b,  terminal  nod- 
ule ;  c,  middle  piece ;  d,  tail ;  e, 
end-piece  of  Retzius  (Bohm  and 
Davidoff). 


at  once  begins  the  process  of  cell  division  or  segmentation y 
which  is  the  first  step  in  the  development  of  the  embryo. 


REVIEW    QUESTIONS 


Name  the  male  organs  of  generation. 
What  is  the  prostate  gland? 


THE  MALE    ORGANS   OF  GENERATION  293 

What  relation  does  it  have  to  the  urethra? 

What  are  Cowper's  glands? 

Describe  the  penis. 

What  is  erectile  tissue? 

Describe  the  testes. 

What  is  the  tunica  vaginalis? 

What  are  the  seminiferous  tubules? 

Describe  the  epididymis. 

What  is  the  vas  deferens? 

What  is  the  scrotum? 

Describe  the  seminal  vesicles. 

Describe  the  semen. 

What  are  spermatozoa? 

What  is  the  function  of  the  spermatozoon? 

Describe  the  fertilization  of  the  ovum. 


CHAPTER    XIII 

REPAIR  AND  WASTE-NUTRITION— ANIMAL 
HEAT— PERSPIRATION— THE  POWER  THAT 
SUPPORTS  AND  PRESERVES  HEALTH 

Having  studied  concisely  the  complex  nature  of  man, 
both  as  regards  the  substances  of  which  he  is  composed 
and  the  organs  that  go  to  make  up- his  body,  and  having 
briefly  pointed  out  the  different  functions  of  many  of  the 
organs  and  parts  described,  we  will  now  turn  our  attention 
to  a  consideration  of  the  power  that  keeps  the  organs  in 
motion — the  phenomenon  that  essentially  constitutes  life. 

We  have  shown  that  each  organ  of  the  body  is  charged 
with  the  performance  of  an  office  or  a  function.  Now, 
the  performance  of  a  function  implies  both  an  action  and 
the  power  to  act,  for  without  action  there  could  be  no 
performance,  and  without  the  power  to  act  there  could  be 
no  action.  ,It  is  clear,  therefore,  that  there  must  be  a 
power  either  invested  in  or  furnished  to  the  organs  that 
enables  them  to  act.  It  is  this  power,  which  may  be 
termed  the  living  power,  vital  power,  or  power  of  life  that 
we  will  now  consider.  The  various  terms  applied  to  it 
are  here  used  synonymously,  and  must  always  be  under- 
stood as  referring  to  that  power  or  principle  by  which 
the  vital  actions  are  maintained  and  life  sustained. 

Waste  is  continually  going  on  in  our  bodies;  that 
is,  the  substances  that  make  up  the  body  are  constantly 
being  exhausted  by  the  activity  of  the  riervomuscular 
apparatus,  and  thus  arises  the  necessity  for  our  taking 
food.     The  phenomena  of  this  waste  of  the  substance  of 

294 


REPAIR   AND    WASTE  2g$ 

our  tissues  is  a  matter  of  interest  to  the  general  reader  as 
well  as  to  the  nurse,  and  a  study  of  the  subject  will  afford 
much  information  that  will  be  available  to  any  who  are 
seeking  to  acquire  a  knowledge  of  our  physiologic  consti- 
tution. 

The  necessity  of  supplying  matter  to  the  system  arises 
from  another  necessity^that  of  the  generation  of  force. 
It  may  thus  be  remarked  that  all  available  or  active  phy- 
sical force,  displayed  in  the  voluntary  or  involuntary  mo- 
tions of  our  bodies,  is  derived  from  the  force  of  the  several 
affinities  of  the  primary  elements  that  enter  into  the  struc- 
tures. 

By  distributing  the  static  state  of  the  chemic  forces 
power  is  generated.  All  the  materials  that  have  their 
affinities  thus  exhausted  become  useless  in  the  position 
they  occupy,  and  must  be  replaced  by  other  or  fresh 
materials.  Here,  then,  is  the  source  of  waste.  Thus, 
it  may  again  be  said,  a  constant  interchange  of  material 
takes  place  in  the  very  substance'  of  our  tissues,  new 
material  from  without  replacing  old  and  effere  substances 
that  have  become  so  in  the  generation  of  force. 

It  is  this  vital  principle  that  prescribes  the  formulae 
for  these  chemic  changes,  according  as  the  involuntary 
actions  or  motions  of  the  body  may  require  force,  or  as 
the  mind  may  call  upon  the  voluntary  muscles  to  expend 
force.  If  you  reflect  for  a  moment  you  will  realize  that 
you  cannot  act,  move,  or  even  think  without  demanding 
the  sacrifice  or  destruction  of  a  portion  of  your  body  equal 
in  extent  to  such  motion,  whether  it  be  of  the  mind  or  of 
the  body.  Thus  we  constantly  die  while  we  live,  and  in 
•this  we  form  a  complete  analogy  to  the  entire  order  of 
organic  life. 

Excretion. — The  materials,  after  having  undergone 
the  metamorphosis  and  having  been  neutralized  by  the 
readjustment  of  their  affinities,  now  require  to  be  removed 


296      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

to  prevent  the  obstruction  they  would  otherwise  give 
rise  to. 

These  materials  may  be  compared  to  the  ashes  of  a 
furnace — they  are  the  result  of  combustion  or  oxida- 
tion. They  are  absorbed  from  the  circulation  by  means, 
principally,  of  the  sudorific  glands,  and  carried  off  by  what 
is  called  cutaneous  transpiration,  or  perspiration.  Mucous 
surfaces,  especially  those  of  the  alimentary  canal,  also 
secrete  from  the  circulation  pecant  or  exhausted  materials 
and  eliminate  them  in  the  dejecta. 

Pulmonary  transpiration  corresponds  to  the  chimney 
of  the  furnace — it  gives  off  the  smoke  or  carbon  dioxid 
and  other  consumed  material.  The  kidneys  remove 
saline  and  acrid  products  of  the  tissue  metamorphosis 
that  are  similar  to,  but  much  more  irritating  than,  the 
perspirable  fluid. 

NUTRITION 

The  processes  of  nutrition  and  the  necessity  for  the 
continued  supply  of  material  have  already  been  dwelt 
upon.  The  source  of  nutrition,  as  has  been  stated- 
elsewhere,  lies  in  food.  A  question  regarding  nutrition 
that  still  remains  unanswered  is.  What  is  the  precise 
modus  operandi  of  nutrition? 

By  the  action  of  the  various  acids,  salts,  and  other 
secreted  products  of  animal  combustion,  which  are  fur- 
nished by  the  glandular  viscera,  as  the  liver,  pancreas,  and 
the  lymphatics,  the  food,  or  ingesta,  becomes  admixed 
with  these  secretions  in  the  process  of  digestion  and  the 
course  of  the  circulation,  and  becomes  still  better  fitted  for 
ready  combination  with  the  substances  of  the  tissues. 

There  is  no  force  required  for  this  nutrition,  except 
the  affinity  that  the  several  substances  have  for  one  an- 
other. It  must,  however,  be  understood  that  all  these 
processes  go  on  under  vital  direction  of  these  affinities. 


REPAIR  AND    WASTE  297 

These  latter  are  not  by  any  means  of  a  definite  form,  and 
but  for  vital  direction  they  might  form  very  anomalous 
combinations. 

ANIMAL   HEAT 

The  term  "animal  heat"  we,  in  common  with  other 
writers,  use  here  merely  to  express  the  heat  of  the  body, 
without  attempting  to  distinguish  one  animal  from 
another.  Its  generation  in  the  system  is  of  vast  im- 
portance to  health,  over  which  it  exercises  a  most  control- 
ling influence.  It  is  proper,  therefore,  that  we  consider 
the  subject  somewhat  at  length  here. 

The  generation  of  animal  heat  has  been  referred  to  in 
a  previous  chapter,  where  the  agency  of  oxygen  in  the 
metamorphosis  or  change  of  materials  composing  the  tis- 
sues of  the  organs  was  discussed.  It  may  here  be  said 
that  in  the  course  of  all  these  changes  modifications  are 
constantly  taking  place  in  the  relative  condition  of  caloric, 
whether  sensible  or  latent  in  its  state.  Oxygen  has  never 
been  known  to  combine  with  any  other  element  without  af- 
fecting, to  some  degree,  the  temperature  of  the  substances 
concerned.  In  the  animal  body,  it  is  true,  oxidation 
never  goes  on  so  rapidly  as  in  conflagrations  in  the  open 
air;  yet,  as  may  be  seen  in  the  process  of  respiration  alone, 
a  great  amount  of  oxygen  is  taken  into  the  system,  but  it 
is  breathed  out  again  with  the  expired  air,  not,  however, 
in  the  same  form  in  which  it  was  taken  in:  it  is  simply 
being  mechanically  received  and  combined  with  nitrogen, 
and  given  off  chemically  united  with  carbon  in  the  form  of 
carbon  dioxid.  While  it  is  known  that  such  a  combination 
of  oxygen  and  carbon  cannot  take  place,  either  in  or  out 
of  the  body,  without  causing  the  evolution  of  a  large 
amount  of  heat,  it  is  by  no  means  difficult  to  believe  that 
what  is  called  animal  heat  has  its  source  in  this  phenome- 
non.    It  may  be  well  to  suggest  that  the  union  that  occurs 


298      ANATOMY  AND   PHYSIOLOGY  FOR  NURSES 

between  the  oxygen  of  the  atmosphere  and  the  blood  in 
the  lungs  is  one  of  a  semimechanical  character,  very 
similar  to  that  previously  existing  between  the  oxygen  and 
the  nitrogen  in  the  atmosphere. 

Oxygen  does  combine  with  the  blood  in  the  lungs ;  this 
is  shown  by  the  change  it  produces  in  the  color  and  con- 
sistence of  this  fluid;  these  changes  have  been  seen  to 
take  place  in  experiments  exposing  venous  blood  to  the 
action  of  oxygen  outside  the  body.  It  must,  however, 
be  evident  that  this  combination  occurs  with  the  mass  of 
the  blood,  and  not  between  this  element  and  the  individual 
constituents  of  the  vital  fluid.  In  the  latter  case  the  effects 
must  of  necessity  be  quite  different  from  those  that  take 
place  in  the  lungs. 

It  is  a  fact,  which  appears  to  be  self-evident,  that  the 
combustion  of  oxygen  and  carbon,  whereby  carbon  dioxid 
is  formed,  takes  place  after  the  oxygen  is  carried  by  the 
circulation  into  the  capillary  vessels,  for  it  is  here  that  the 
peculiar  effects  of  the  workings  of  this  process  are  evinced. 
It  is  in  this  part  of  its  passage  that  the  blood  undergoes  its 
remarkable  change,  and  it  is  here  that  it  acquires  its  dark 
purple  color;  it  is  at  this  time,  too,  that  carbon  dioxid, 
which  is  the  evidence  of  combustion,  or  the  chemic  unit 
of  oxygen  and  carbon,  is  present.  If  the  point  of  origin 
of  the  process  of  oxidation,  here  said  to  be  the  cause  of 
the  evolution  of  animal  heat,  is  traced,  it  will  be  found  that 
instead  of  the  phenomenon  occurring  entirely  within  the 
lungs,  it  takes  place  through  the  system — in  every  tissue 
and  organ  of  the  entire  body. 

In  the  circulation  of  the  blood  we  find  that  two  import- 
ant changes  occur;  these  might  be  said  to  take  place  at 
entirely  opposite  points.  By  one  of  these  changes  the 
color  of  the  blood  is  altered  to  a  marked  red;  by  the  other, 
to  a  dark  or  purple  red ;  and  it  is  this  last-named  change, 
and  not  the  first,  that  indicates  the  specific  office  of  the 


REPAIR  AND    WASTE  299 

oxygen.  In  fact,  as  before  stated,  the  agency  of  the  oxygen 
is  concerned  in  the  general  metamorphosis  of  the  tissues. 
In  this  process  we  at  once  find  an  evolution  of  heat  and 
energy,  which  is  the  result  of  this  phenomenon. 

Heat  is  disseminated  with  more  or  less  rapidity  through 
all  bodies,  varying  according  to  their  density,  but  in 
general  more  easily  penetrating  those  that  are  solid  than 
those  that  are  porous.  Thus,  the  amount  of  heat  is  never 
constant,  but  is  continually  passing  and  repassing  through 
matter,  seeking  an  equilibrium  or  level.  The  human  body 
is  also  subject  to  the  same  law;  and  as  heat  is  constantly 
being  generated  in  its  tissues,  it  must  also  as  constantly 
be  eliminated ;  and  mce  versa,  for  the  very  reason  that  it  is 
thus  perpetually  being  removed,  it  must  be  continually 
generated.  Thus,  since  the  exercise  of  the  day  has  dimin- 
ished the  force  or  quantity  of  the  living  power,  the  neces- 
sity arises  for  rest  to  restore  it  during  the  night.  During 
sleep  the  functions  are  performed  in  a  slower  and  more 
feeble  manner,  or  cease  entirely;  animal  heat  is  less  rapidly 
evolved;  the  living  power  accumulates;  the  organs  re- 
cover their  tone,  and  the  whole  vital  energies  are  con- 
centrated, ready  to  meet  the  exigencies  of  the  coming 
day. 

PERSPIRATION 

In  a  previous  chapter  we  have  already  discussed  the 
effects  of  any  check  to  the  perspiratory  functions.  Never- 
theless, in  order  to  make  the  subject  more  clear,  we  will 
consider  it  again  in  detail,  although  in  doing  so  some  repe- 
titions will  necessarily  occur. 

The  perspiratory  excretion  exerts  an  important  influ- 
ence on  the  integrity  of  the  living  organism.  A  sudden 
check  or  prolonged  retention  of  it  in  the  body  is  certain  to 
produce  more  or  less  serious  derangement  of  the  functions. 
There  is  no  disease,  perhaps,  in  which  the  perspiratory 
function  is  not  in  some  measure  affected. 


300     ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

The  perspirable  fluid,  or  sweat,  is  excreted  from  the 
blood,  which  later,  through  this  process,  is  kept  in  a  state 
of  purity  (see,  in  a  previous  chapter,  the  section  devoted 
to  the  appendages  of  the  skin).  As  has  been  said  else- 
where, the  organs  that  separate  the  perspirable  fluid  from 
the  blood  are  the  sudorific  glands;  these  absorb  the  watery 
poison  of  the  blood  from  the  capillaries  or  interstices  of 
the  tissues. 

The  perspiratory  process,  as  has  been  said,  is  one  of 
immense  importance  to  the  living  body.  Its  principal 
uses  are: 

First:  To  moisten  the  external  surfaces  of  the  body. 
Every  part  of  the  system — the  internal  surfaces,  even  the 
very  substance  of  the  organs  themselves,  and  the  exter- 
nal skin — ^requires  a  certain  degree  of  moisture  to  lubri- 
cate, soften,  and  qualify  it  for  the  performance  of  its  func- 
tions. Too  great  a  dryness  of  the  skin  injures  the  epider- 
mis, or  scarf-skin,  and  the  termination  of  the  papillae 
or  ends  of  the  nerves,  which  impairs,  and  ultimately 
injures,  the  true  skin  and  diverts  sensation. 

Second :  To  remove  the  worn-out  material  from  the  system. 
By  this  process  the  effete  substances  and  those  which  are 
no  longer  useful  are  removed,  thereby  cleansing  and  puri- 
fying the  living  tissue;  relieving  it  of  a  mass  of  morbid 
putrefactive  matter,  which,  if  retained  in  the  system,  would 
eventually  interrupt  the  play  of  the  organs,  prove  a  source 
of  irritation  to  their  structure,  and  undoubtedly  cause 
disease.  By  this  process  the  blood  and  all  the  other  fluids 
are  purified,  and  kept  in  a  condition  most  conducive  to 
sound  health.  The  perspiratory  organs  may  justly  be 
regarded  as  the  principal  natural  outlets  or  emunctories 
for  the  surplus  matter  that  is  continually  accumulating 
in  the  blood. 

Third :  To  remove  poisonous  or  other  irritating,  extraneous 
matter  from  the  body.     We  have  previously  pointed  out 


REPAIR  AND    WASTE  3OI 

the  method  by  which  everything  entering  the  body  is 
removed  from  the  system.  Whatever  is  received  into  the 
stomach  passes  to  the  intestine,  a  portion  going  thence 
through  the  lacteals  and  thoracic  duct  into  the  blood; 
the  gaseous  substances,  which  enter  the  lungs,  pass  di- 
rectly from  these  organs  into  the  blood.  Solid  and  liquid 
poisons  usually  enter  the  body  through  the  mouth  and 
stomach,  and  gaseous  ones  by  way  of  the  lungs.  How, 
then,  when  a  poison  has  penetrated  the  system,  does 
nature  expel  it?  If  the  poison  is  a  liquid  or  a  solid  sub- 
stance taken  into  the  stomach,  the  irritation  it  produces 
or  the  administration  of  an  emetic  may  induce  vomiting, 
thus  ejecting  it  before  any  part  is  absorbed,  and  so  saving 
the  system  from  further  ill  effects.  But  if  the  irritant  be 
a  gas  taken  into  the  lungs,  or  if  the  poison  has  had  time  to 
enter  the  circulation  before  vomiting  takes  place,  it  must 
then  be  removed  from  the  system,  through  the  grand 
emunctories  of  the  blood — the  perspiratory  organs;  that  is, 
it  must  pass  off  with  the  perspiration.  But  for  this  most 
admirable  provision  of  nature  to  cleanse,  to  purify,  to 
drain  off  extraneous  matter,  death  would  ensue. 

Fourth:  Another  important  use  of  the  perspiration  is 
to  regulate  the  temperature  of  the  body.  It  has  already  been 
shown  that  much  heat  is  abstracted  by  the  process  of 
evaporation.  It  cannot  but  have  been  observed  by  every 
one  how  readily  exercise  is  followed  by  perspiration. 
This,  therefore,  is  nature's  method  of  regulating  the  heat 
of  our  bodies  and  thus  dissipating  fevers. 

Failure  on  the  part  of  the  perspiratory  organs  to 
perform,  in  any  degree,  their  functions  causes  a  retention 
in  the  system  of  matters  whose  presence  is  exceedingly 
injurious,  for  putrefaction  is  apt  to  occur,  whereby  all  the 
fluids  of  the  body  will  become  contaminated,  their  stimu- 
lating qualities  weakened,  and  all  the  secretions  so  neces- 


302      ANATOMY  AND   PHYSIOLOGY  FOR   NURSES 

sary  to  maintain  the  vital  actions  of  the  system  will  be- 
come vitiated. 

When  the  function  of  perspiration  is  impaired,  good 
health  can  never  be  enjoyed ;  hence  the  propriety  of  wash- 
ing, bathing,  frictions,  to  soften  and  relax  the  skin,  in 
which  are  situated  the  organs  that  separate  the  perspira- 
tory fluid  from  the  blood. 

THE   POWER   THAT   SUPPORTS   AND   PRESERVES 
HEALTH 

It  must  be  evident  to  the  reader  who  has  carefully 
perused  the  foregoing  pages  that  the  preserving  power  of 
health  can  be  nothing  more  than  the  living  power  of  the 
system  exercising  its  full  and  wholesome  influence  over  the 
vital  organs,  by  which  they  are  kept  in  a  healthy  condition. 
This  power,  although  depending  upon  matter  exterior  to 
the  body,  may  be  said  to  be  exerted  internally;  conjointly 
with  which  are  many  causes  having  an  influence  upon 
health  that  depend  upon  the  reasoning  faculties  and  the 
influence  of  the  will.  These  are,  principally,  a  suitable 
degree  of  exercise  and  rest;  the  rational  indulgence  of  the 
propensities  and  passions;  and,  in  short,  the  due  observ- 
ance of  temperance  in  everything  that  is  capable  of  pro- 
ducing either  a  moral  or  a  physical  effect  upon  the  sys- 
tem. 

REVIEW    QUESTIONS 

What  are  waste  products? 

Through  what  channels  do  they  pass  out  of  the  system? 

What  means  are  required  to  supply  waste? 

What  conditions  exist  when  the  body  becomes  fatigued? 

What  waste  products  are  cast  off  from  the  lungs? 

What  waste  products  pass  out  through  the  kidneys? 

Does  the  digestive  tract  enter  into  the  formation  of  waste  products? 

What  is  nutrition? 

What  organs  are  concerned  in  sustaining  nutrition? 


PHYSIOLOGIC  CONSTANTS  303 

Has  affinity  any  power  in  its  production? 

What  is  regarded  as  animal  heat? 

How  is  heat  generated  in  the  body? 

What  takes  place  when  oxygen  is  combined  with  carbon? 

Where  does  the  blood  take  on  its  dark  color? 

What  two  changes  take  place  in  the  blood  in  one  revolution  of  the 
same? 

With  these  changes,  what  supply  is  provided  to  the  system? 

Why  does  the  system  require  rest?    • 

What  takes  place  in  the  system  while  we  sleep? 

What  is  produced  when  free  perspiration  is  brought  about? 

Should  there  be  a  blocking-up  of  the  perspiration?  What  would 
follow? 

When  poison  is  taken  into  the  system,  why  is  the  skin  one  of  the  im- 
portant routes  of  elimination? 

If  the  poison  remains  in  the  system  for  a  great  length  of  time,  what  is 
the  best  means  to  eliminate  it? 

Is  the  temperature  of  the  body  influenced  by  perspiration? 

What  are  required  for  the  maintenance  of  good  health? 

TABLE  OF  PHYSIOLOGIC  CONSTANTS.— (Srwia^&er.) 

Mean  height  of  male:  5  feet  6§  inches;  of  female:  5  feet  2  inches. 

Mean  weight  of  male:  145  pounds;  of  female:  121  pounds. 

Number  of  c hemic  elements  in  the  human  body:  From  16  to  18. 

Number  of  proximate  principles  in  the  human  body:  About  100. 

Amount  of  water  in  a  body  weighing  145  pounds:  108  pounds. 

Amount  of  solids  in  a  body  weighing  145  pounds:  36  pounds. 

Amount  of  saliva  secreted  in  twenty-four  hours:  About  3^  pounds. 

Function  of  saliva:  Converts  starch  into  maltose. 

Active  principle  of  saliva:  Ptyalin. 

Amount  of  gastric  juice  secreted  in  twenty-four  hours:  From  8  to  14  pounds. 

Function  of  gastric  juice:  Converts  albumin  into  peptone. 

Active  principles  of  gastric  juice:  Pepsin  and  hydrochloric  acid. 

Duration  of  digestion:  From  three  to  five  hours. 

Amount  of  intestinal  juice  secreted  in  twenty-four  hours:  About  i  pound. 

Function  of  intestinal  juice:  Converts  starch  into  maltose. 

Amount  of  pancreatic  juice  secreted  in  twenty-four  hours:  About  i\  pounds. 

Active  principles  of  pancreatic  juice:  Trypsin,  amylopsin,  and  steapsin. 

Functions  of  pancreatic  juice:  i.  Emulsifies  fats.     2.  Converts  albumin 

into  peptone.     3.  Converts  starch  into  maltose. 
Amount  of  bile  poured  into  the  intestines  daily:  About  2\  pounds. 


304      ANATOMY  AND  PHYSIOLOGY  FOR  NURSES 

Functions  of  bile:  i.  Assists  in  the  emulsification  of  fats.  2.  Stimulates 
the  peristaltic  movements.  3.  Prevents  putrefactive  changes  in  the 
food.     4,  Promotes  the  absorption  of  the  fat. 

Amount  of  blood  in  the  body:  From  16  to  18  pounds. 

Size  of  red  corpuscles:  j-^^-q  of  an  inch. 

Size  of  white  corpuscles:  ^500  inch. 

Shape  of  red  corpuscles:  Circular  biconcave  disks. 

Shape  of  white  corpuscles:  Globular. 

Number  of  red  corpuscles  in  a  cubic  millimeter  {the  cubic  -f^  inch  of  blood): 

5,0CXD,000. 

Function  of  red  corpuscles:  To  carry  oxygen  from  the  lungs  to  the  tissues. 

Frequency  of  the  heart's  pulsation  a  minute:  72  on  the  average. 

Velocity  of  the  blood  movement  in  the  arteries:  About  1 2  inches  a  second. 

Length  of  time  required  for  the  blood  to  make  an  entire  circuit  of  the  vascu- 
lar system:  About  twenty  seconds. 

Amount  of  air  passing  in  and  out  of  the  lungs  at  each  respiratory  act: 
From  20  to  30  cubic  inches. 

Amount  of  air  that  can  be  taken  into  the  lungs  on  a  forced  inspiration: 
no  cubic  inches. 

Amount  of  reserve  air  in  the  lungs  after  an  ordinary  expiration:  no  cubic 
inches. 

Amount  of  residual  air  always  remaining  in  the  lungs:  About  100  cubic 
inches. 

Vital  capacity  of  the  lungs:  About  250  cubic  inches. 

Entire  volume  of  air  passing  in  and  out  of  the  lungs  in  twenty-four  hours: 
About  400  cubic  feet. 

Composition  of  air:  Nitrogen,  79.19;  oxygen,  20.81,  in  100  parts. 

Amount  of  oxygen  absorbed  in  twenty-four  hours:  18  cubic  feet. 

Amount  of  carbonic  acid  exhaled  in  twenty-four  hours:  14  cubic  feet. 

Temperature  of  the  human  body  at  the  surface:  98.6°  Fahrenheit. 

Amount  of  urine  excreted  daily:  From  40  to  50  ounces. 

Amount  of  urea  excreted  daily:  512  grains. 

Specific  gravity  of  urine:  From  1.015  to  1.025. 

Number  of  spinal  nerves:  31  pairs. 

Number  of  roots  of  origin:  Two — first,  anterior,  efferent;  second,  pos- 
terior, afferent. 

Rate  of  transmission  of  nerve  force:  About  100  feet  a  second. 

Number  of  cranial  nerves:  Twelve  pairs. 

Nerves  of  special  sense:  i.  Olfactory,  or  first  pair.  2.  Optic,  or  second 
pair.  3.  Auditory,  or  eighth  pair.  4.  Chorda  tympani  for  anterior 
two-thirds  of  tongue.  5.  Branches  of  glossopharyngeal,  or  eighth 
pair,  for  posterior  one-third  of  tongue. 


PHYSIOLOGIC  CONSTANTS  305 

Motor  nerves  to  eyeball  and  accessory  structures:  Motor  oculi,  or  third 

pair;  pathetic,  or  fourth  pair;  abducens,  or  sixth  pair. 
Motor  nerve  to  facial  muscles:  Portio  dura,  facial,  or  seventh  pair. 
Motor  nerve  to  tongue:  Hypoglossal,  or  twelfth  pair. 
Sensory  nerve  of  the  face:  Trifacial,  or  fifth  pair. 
Sensory  nerve  of  the  pharynx:  Glossopharyngeal,  or  ninth  pair. 
Sensory  nerves  of  the  lungs,  stomach,  etc.:  Pneumogastric,  or  tenth  pair. 
Length  of  spinal  cord:  16  to  18  inches;  weight,  ij  ounces. 
Point  of  decussation  of  motor  fibers:  At  the  medulla  oblongata. 
Point  of  decussation  of  sensory  fibers:  Throughout  the  spinal  cord. 
Function  of  the  anterolateral  columns  of  the  spinal  cord:  Transmit  motor 

impulses  from  the  brain  to  the  muscles. 
Functions  of  the  posterior  columns:  Assist  in  the  co-ordination  of  muscular 

movements. 
Functions  of  the  medulla  oblongata:  Controls  the  functions  of  insalivation, 

mastication,  deglutition,  respiration,  circulation,  etc. 
Function  of  the  cerebellum:  Center  for  the  co-ordination  of  muscular 

movements. 
Function  of  the  cerebrum:  Center  for  intelligence,  reason,  and  will. 
Center  for  articulate  language:  Third  frontal  convolution  on  the  left  side 

of  the  cerebrum. 
Number  of  coats  to  the  eye:  Three — first,  cornea  and  sclerotic;  second, 

choroid  and  iris;  third,  retina. 
Function  of  iris:  Regulates  the  amount  of  light  entering  the  eye. 
Function  of  crystalline  lens:  Refracts  the  rays  of  light  so  as  to  form  an 

image  on  the  retina. 
Function  of  retina:  Receives  the  impression  of  light. 
Function  of  the  membrana  tympani:  Receives  and  transmits  waves  of 

sound  to  the  internal  ear. 
Function  of  the  Eustachian  tube:  Regulates  the  passage  of  air  into  and 

from  the  middle  ear. 
Function  of  the  semicircular  canals:  Assist  in  maintaining  the  equipoise 

of  the  body. 
Function  of  the  cochlea:  Appreciates  the  shades  and  combinations  of 

musical  tones. 
Size  of  human  ovum:  j^-^  inch  in  diameter. 
Size  of  spermatozoon:  5^^  inch  in  length. 
Function  of  placenta:  Acts  as  a  respiratory  and  digestive  organ  for  the 

fetus. 
Duration  of  pregnancy:  Two  hundred  and  eighty  days. 


20 


INDEX 


Abdomen,  muscles  of,  66 
action,  67 

regions  of,  177 
Abdominal  aorta,  97,  1 1 1 

cavity,  32 
Abducens  nerve,  221 
Abductor  minimi  digiti  muscle, 

75 
pollicis  muscle,  75 

Accommodation,  260 

Acetabulum,  34 

Acini  of  mammary  glands,  247 

Acromion  process,  34 

Adductor  longus  brevis,  80 
magnus,  80 
obliquus  pollicis  muscle,  75 
transversus  pollicis  muscle,  75 

Adenology,  definition,  12 

Adipose  tissue,  47 

Air-cells,  131 

Albuminoids  of  blood,  135 

Albuminuria,  189 

Alimentary  tract,  155 

Alveoli,  131 

Amylopsin,  172 

Anabolism,  181 

Anatomic  neck  of  humerus,  37 

Anatomy,  definition,  11,  12 

Anconeus  muscle,  74 

Angiology,  definition,  12 

Angular  artery,  100 

Animal  heat,  297 

Annular  ligaments,  84 

Anterior  annular  ligament,  84 


Anterior  auricular  artery,  102 

cerebral  artery,  104,  214 

chamber  of  eye,  256 

crural  nerve,  227 

cutaneous  nerve,  227 

fontanel,  26 

horns  of  spinal  cord,  219 

jugular  vein,  123 

meningeal  artery,  104,  215 

nares,  267 

superior  spine  of  ilium,  34 

tibial  artery,  116 
nerve,  229 

ulnar  vein,  124 

vertebral  muscles,  64 
Antrum  of  Highmore,  28 
Anus,  169 
Aorta,  91,  96 

abdominal,  97,  iii 

arch  of,  96 

ascending,  97 

branches  of,  91,  92,  96-98 

descending,  97 

thoracic,  97,  no 

transverse,  97 
Aponeuroses,  47,  53 
Appendages  of  eye,  258 

of  skin,  194 

of  uterus,  279 
Appendix  vermiformis,    168 

xiphoid,  30 
Aqueous  humor,  253,  256 
Arachnoid,  1-98 

membrane,  209,  217 

307 


3o8 


INDEX 


Arbor  vitae,  199,  213 
Arch  of  aorta,  96 

of  vertebrae,  22,  23 

zygomatic,  28 
Areola  of  breasts,  246 
Arm,  bones  of,  37 

veins  of,  124,  125 
deep,  125 
superficial,  124 
Arterise  receptaculi,  103 
Arterial  system,  93,  94 
Arteries,  93,  94 

blood  in,  direction  of,  93 

blood-supply  of,  96 

coats  of,  95 

sheath  of,  96 

structure  of,  95 
Artery,  medullary,  17 
Articular  cartilage,  16 

eminences  of  bones,  20 

synovial  membranes,  252 
Ascending  aorta,  97 

colon,  169 

pharyngeal  artery,  102 
Astigmatism,  261 
Astragalus,  41 
Atlas  of  spine,  23 
AttoUens,  57 
Attrahens,  57 
Auditory  artery,  215 

canal,  261,  262 

nerve,  222 

organs,  261 
Aurem  muscles,  57 
Auricle  of  ear,  261 
Auricles,  88,  89 
Auricular  artery,  anterior,  102 
posterior,  102 

muscles,  57 

vein,  posterior,  122 
Axillary  artery,  104,  107 

glands,  233 


Axillary  plexus,  225 

vein,  125 
Axis,  celiac,  112 

of  spine,  23 

thyroid,  107 
Azygos  uvulae  muscle,  62 

veins,  120,  128 

Back,  muscles  of,  64 
Ball-and-socket  joints,  45,  46 
Bartholin  glands,  274 
Basilar  artery,  106,  214 
Basilic  vein,  124 
median,  125 
Biaxial  joints,  45 
Biceps  flexor  cubiti  muscle,  71 

muscle,  82 
Bicuspid  valve,  89,  90 
Big  neck,  244 
Bile,  172,  236 

function  of,  172 
Birth,  circulatory  changes  at,  141 
Blackheads,  247 
Bladder,  186 

female,  274 
Blind  pouch  of  large  intestine, 

168 
Blinds  of  eye,  258 
Blood,  131 

albuminoids  of,  135 

alkaline  reaction  of,  132 

arterial,  direction  of,  93 

changes  in,  in  disease,  137 

circulation  of,  87 

clotting  of,  136 

color  of,  131 

composition  of,  132 

corpuscles  of  132.       See  also 
Corpuscles. 

distribution,  132 

fibrin  of,  136 

fibrinogen  of,  136,  137 


INDEX 


309 


Blood,  gases  of,  136 

hemoglobin  of,  133 

in  veins,  120 

liquor  sanguinis  of,  132 

mineral  salts  of,  136 

paraglobulin  of,  136 

plasma  of,  132,  135 

plates,  135 

properties  of,  131 

proteids  of,  135 

quantity  of,  136 

reaction  of,  132 

serum  of,  136 

specific  gravity  of,  132 

temperature  of,  132 
Blood-supply  of  kidneys,  185 
Blood-vessels  of  bone,  17 
Bones,  13 

articular  eminences  of,  20 

blood-vessels  of,  17 

cancellated  tissue  of,  13 

chemical  analysis  of,  14 

classification  of,  20 

composition  of,  14,  15 
age  and,  15 

depressions  of,  20 

development  of,  19 

eminences  of,  20 

flat,  20 

in  rickets,  15 

inorganic  constituents  of,  14, 15 

irregular,  20 

lamellae  of,  13 

line  of,  20 

long,  20 

malar,  28 

marrow  of,  16 

nerves  of,  17 

non-articular  depressions  of,  20 
eminences  of,  20 

of  body,  22 

of  cranium,  24 


Bones  of  face,  24 

of  nose,  266 

of  skull,  24 

of  spine,  22 

of  upper  extremity,  34,  35 

organic  constituents  of,  14,  15 

ridge  of,  20 

sensibility  of,  14 

short,  20 

spine  of,  20 

surfaces  of,  20 

temporal,  27 

tubercle  of,  20 

tuberosity  of,  20 

Wormian,  22 
Brachial  artery,  107,  108 

plexus,  225 

venae  comites,  124 
Brachialis  anticus  muscle,  71 
Brain,  198,  209 

arterial  supply  of,  214 

fornix  of,  212 

interior  of,  211 

lobes  of,  209,  211 

membranes  of,  198,  209 

sinuses  of,  215 

under  surface  of,  211 

ventricles  of,  212 

weight  of,  209 
Breast-bone,  30 

Breasts,    246.     See    also    Mam- 
mary glands. 
Breathing  air  in  lungs,  150 
Bridle  of  tongue,  243 
Bronchi,  146 

in  respiration,  151 
Bronchial  arteries,  1 1 1 
Bronchocele,  244 
Bronzed  skin,  190 
Buccinator  jnuscle,  59 
Bulbus  aortae,  96 
Bursas,  252 


310 


INDEX 


Cancei<I/ATBd  tissue,  13 
Canthi,  258 
Capillaries,  94 

Capillary  attraction,  venous  cir- 
culation and,  120 
Capsule  of  kidney,  1 83 

of  lens,  257 
Caput  gallinaginis,  287 
Cardiac  orifice  of  stomach,  162 

veins,  129 
Carotid  arteries,  99 
artery,  external,  99 
internal,  103,  214 
Carpus,  bones  of,  38 
Cartilage,  16,  43,  45 
articular,  16 
tarsal,  258 
Caruncula  lacrimalis,  259 
Cauda  equina,  203,  218 
Cecum,  168 
Celiac  axis,  112 
Cells,  mastoid,  262 
Cephalic  vein,  125 

median,  125 
Cerebellum,  198,  199,  213 

functions  of,  206 
Cerebral    artery,    anterior,    104, 
214 
middle,  214 
posterior,  215 
hemispheres,  functions  of,  206 
Cerebrospinal  fluid,  210 

nerves,  230 
Cerebrum,  198,  199,  210 
convolutions  of,  210 
cortical  portion  of,  199,  211 
functions  of,  206 
hemispheres  of,  199 

function,  206 
medullary  portion  of,  199,  211 
sulci  of,  210 
Cerumen,  262 


Cervical  ganglia,  230 

vertebrae,  22 
Cervix  uteri,  276 
Chest,  30 
Choroid  coat,  253,  254 

plexuses,  210,  212 
Chyle,  156,  174,  245 
Chyme,  171 
Ciliary  processes,  255 
Circle  of  Willis,  214,215 
Circular  fibers  of  iris,  255 
Circulation,  changes  in,  at  birth, 
141 

fetal,  138 

of  blood,  87 

portal,  130 

pulmonary,  130 
'  venous,  119 
Circulatory  system,  87 

of  fetus,  138 
Circumvallate  papilla  of  tongue, 

266 
Clavicle,  34 
Clavus,  192 
Clitoris,  273 
Clotting  of  blood,  136 
Coats  of  stomach,  162 
Coccygeal  vertebrae,  22 
Coccyx,  33 

articulation  of,  23 
Cochlea,  264 
Cochlear  nerve,  222 
Coefficient  of  ventilation,  151 
Collar-bone,  34 
Colles'  fracture,  37 
Colon,  169 

ascending,  169 

descending,  169 

transverse,  169 
Common  carotid  arteries,  99 

iliac  arteries,  114 
vein,  128 


INDEX 


311 


Complementary  air  in  lungs,  150 
Condyles  of  femur,  40 

of  humerus,  37 
Condyloid  joints,  45 
Conglobate  glands,  233 
Conjunctiva,  259 
Constants,  physiologic,  table  of, 

303-305 
Constrictor  muscles,  63 
Convolutions  of  cerebrum,  210 
Coracobrachialis  muscle,  71 
Coracoid  process,  36 
Corium,  191,  192 
Cornea,  253,  254 
Coronary  artery,  98,  113 
Corpora  cavernosa,  288 

quadrigemina,  213 
Corpus  callosum,  199,  211,  212 

dentatum,  199 

luteum,  284 

spongiosum,  288 

striatum,  213 
Corpuscles,  132 

red,  132,  133 

composition  of,  133 
function  of,  133 

white,  132,  134 
Corrugator  supercilii  muscle,  57 
Cortex  of  kidney,  183 
Cortical  portion  of  cerebrum,  199, 

211 
Cowper's  glands,  287 
Cranial  nerves,  219 
Cranium,  bones  of,  24 
Crassamentum,  132,  136 
Crest  of  ilium,  34 

of  tibia,  40 
Crow's  beak,  36 
Crural  nerve,  227 
anterior,  227 
posterior,  228 
Crureus  muscle,  80 


Crystalline  humor,  253,  256 
Cul-de-sac  of  large  intestine,  168 
Cutaneous  nerve,  anterior,  227 

external,  227 

posterior,  227 
transpiration,  296,  299 

Deep  femoral  vein,  126 
Deglutition,  160 
Deltoid  muscle,  69 
Dental  nerve,  superior,  221 
Depressions  of  bones,  20 
Depressor  anguli  oris  muscle,  59 

labii  inferior  is  muscle,  59 
Derma,  191 

Dermatology,  definition,    12 
Descending  aorta,  97 

colon,  169 
Diabetes,  189 
Diaphragm,  30,  68,  153 
Diaphragmatic  muscles,  68 
Digastric  muscle,  61 
Digestion,  154 

intestinal,  170 
Digestive  system,  154 

tract,  155 
Disease,  blood  changes  in,  137 
Dorsal  ganglia,  231 

interossei  muscle,  76 

nerves,  226 

vertebrae,  22 
Dorsalis  hallucis  artery,  116 

pedis  artery,  116 
Ductus  arteriosus,  141 

venosus,  139,  141 
Duodenum,  165 
Dura  mater,  198,  209,  216 

Ear,  261 
external,  261 
internal,  264 
nerves  of,  264 


312 


INDEX 


Ear-wax,  262 
Eighth  cranial  nerve,  222 
Ejaculatory  duct,  291 
Eleventh  cranial  nerve,  224 
Eminences  of  bones,  20 
Endocardium,  88 
Endosteum,  14,  18 
Ensiform  of  sternum,  30 
Epidemic  parotitis,  242 
Epidermis,  191,  192 
Epididymis,  289 
Epigastric  artery,  superior,  106 

region,  178 
Epimysium,  52 
Epithelium,  191 
Erectile  tissue,  288 
Erythrocytes,  133 

composition  of,  133 

function  of,  133 
Esophageal  arteries,  1 1 1 
Esophagus,  162 
Ethmoid  bones,  27 
Eustachian  tube,  263 
Excretion,  bodily,  295 
Excretory  duct  of  testes,  289 

system,  180 
Extensor  brevis  poUicis  muscle, 

74 
carpi  radialis  brevior  muscle, 

73 
longior  muscle,  71 
ulnaris  muscle,  74 
communis    digitorum    muscle, 

73 

indicis  muscle,  74 

longus   digitorum   muscle,    83 
hallucis  muscle,  83 
poUicis  muscle,  74 

minimi  digiti  muscle,  73 

ossis   metacarpi   pollicis   mus- 
cle, 74 
External  annular  ligament,  84 


External  auditory  meatus,  261, 
262 

carotid  artery,  99 

coat  of  arteries,  95 

cutaneous  nerve,  227 

ear,  261 

iliac  artery,  115 
vein,  126,  128 

intercostal  muscle,  68 

jugular  vein,  120,  123 

layer  of  retina,  256 

musculocutaneous  nerve,  229 

oblique  muscle,  66 

plantar  nerve,  228 

popliteal  nerve,  228 

pterygoid  muscle,  60 
Eyeball,  253,  254 
Eyebrows,  258 
Eyelashes,  259 
Eyelids,  258 
Eyes,  253 

appendages  of,  258 

Face,  bones  of,  24 

muscles  of,  55 
Facial  artery,  100 
transverse,  102 

nerve,  221 

vein,  121 
Fallopian  tubes,  279 
False  ribs,  31 
Falx  cerebelli,  198 

cerebri,  198,  199 
Far-sightedness,  261 
Fasciae,  47 

Fasciculi  of  muscle,  52 
Fat,  47 

Female  organs  of  generation,  271 
Femoral  artery,  115 

muscles,  77,  80,  82 

nerve,  227 

vein,  126 


INDEX 


3^3 


Femoral  vein,  deep,  126 

Femur,  38 

Fenestra  ovalis  of  ear,  264 
rotunda  of  ear,  264 

Fertilization  of  ovum,  291 

Fetal  circulation,  138 

Fetus,  lungs  of,  140 
uterus  of,  277 
vascular  system  of,  138 

Fibers  of  iris,  255 

Fibrin  of  blood,  136 

Fibrinogen  of  blood,  136 

Fibrocartilages  of  nose,  266 

Fibula,  40 

Fifth  cranial  nerve,  220 

Filiform  papilla  of  tongue,  266 

Fimbriae  of  oviducts,  280 

Fimbriated   extremity  of   Fallo- 
pian tubes,  280 

Fingers,  bones  of,  38 

First  cranial  nerve,  219 

Fissura  palpebrarum,  258 

Fistula,  lacrimal,  260 

Flat  bones,  20 

Flexor  brevis  minimi  digiti  mus- 
cle, 75 
poUicis  muscle,  75 
carpi  radialis  muscle,  72 

ulnaris  muscle,  72 
longus  pollicis  muscle,  73 
profundus    digitorum    muscle, 

73 

sublimis  digitorum  muscle,  73 
Flexure,  sigmoid,  169 
Floating  ribs,  31 
Fluids  of  eye,  253 
Fontanel,  anterior,  26 

posterior,  26 
Foot,  bones  of,  41 

ligaments  of,  44 

muscles  of,  79,  84 
Foramen  magnum,  25 


Foramen  of  Monro,  212 

ovale  at  birth,  141 
Forearm,  bones  of,  36 

muscles  of,  72 
Foreskin,  288 
Fornix  of  brain,  212 
Fossa,  nasal,  267 
Fourth  cranial  nerve,  219 
Fracture,  Colics',  37 

greenstick,  15 

Potts',  40 
Frenum  of  tongue,  243 
Frontal  bone,  25 

vein,  121 
Fundus  of  uterus,  276 
Fungiform  papilla  of  tongue,  266 

Gall-bIvAddER,  236,  237 
Ganglia,  204,  230 
Ganglion,  Gasserian,  221 
Ganglionic  nerve,  230 
Gases  of  blood,  136 
Gasserian  ganglion,  211 
Gastric  artery,  113 

glands,  164,  165 

juice,  162 

action  of,  165 
composition  of,  164 
Gastrocnemius  muscle,  83 
Gemellus  inferior  muscle,  81 

superior  muscle,  81 
Generation,  female  organs  of,  271 

male  organs  of,  287 
Genesiology,  definition,  12 
Geniohyoglossus  muscle,  62 
Geniohyoid  muscle,  62 
Genital  nerve,  227 
Genitalia,  female,  271 

male,  287 
Genitocrural  nerve,  227 
Gladiolus  of  sternum,  30 
Glands,  233 


314 


INDEX 


Glands,  Cowper's,  287 

of  Bartholin,  274 

of  Lieberkiihn,  172 
Glandular  system,  233 
Glans  penis,  288 
Glenoid  cavity,  35 
Gliding  joints,  45,  46 
Glomerulus  of  kidney,  183 
Glossopharyngeal  nerve,  222 
Gluteal  muscles,  80 
Gluteus  maximus  muscle,  80 

medius  muscle,  81 

minimus  muscle,  81 
Goiter,  244 

Graafian  vesicles,  281,  282 
Gracilis  muscle,  80 
Gray  commissure,  219 
Great  sciatic  nerve,  228 

sympathetic  nerve,  229 
Greenstick  fracture,  15 
Gustatory  nerve,  264 

Hair,  194 

Hand,  bones  of,  37 

muscles  of,  74 

sense  of  touch  and,  269 
Haversian  canals,  14,  16,  17 
Head,  ganglia  of,  230 

muscles  of,  55,  56 

of  femur,  38 

of  fibula,  40 

of  humerus,  37 

veins  of,  121 
Health,  power  that  supports,  302 

preservation  of,  302 
Hearing,  organ  of,  261 
Heart,  87 

cavities  of,  88 

opening  of,  93 

valves  of,  89 
Heart-beat,  93 
Heat,  bodily,  297 


Heel-bone,  42. 
Hemoglobin,  133 
Hepatic  artery,  113 
Highmore,  antrum  of,  28 
Hinge-joints,  45 
Hip,  muscles  of,  77 
Horns  of  spinal  cord,  219 
House-maids'  knee,  41 
Humerus,  37 

Humors  of  eye,  253,  256,  257 
Hyaloid,  257 
Hydrocephalus,  212 
Hymen,  273 

imperforate,  274 
Hyoglossus  muscle,  62 
Hyoid  bone,  29,  30 
Hyperopia,  261 
Hypochondriac  region,  left,  178 

right,  177 
Hypogastric  region,  178 
Hypoglossal  nerve,  224 

Ileocecal  valve,  169 

Ileum,  166 

Iliac  arteries,  common,  114 

muscles,  76 

vein,  common,  128 
external,  126,  128 
internal,  128      ' 
Iliacus  muscle,  77 
Iliohypogastric  nerve,  226 
Ilio-inguinal  nerve,  226 
Ilium,  34 

crest  of,  34 
Imperforate  hymen,  274 
Impregnation,  291 
Incus,  262 
Inferior  constrictor  muscle,  63 

maxillary  bone,  29 
muscles,  59 
nerve,  221 

meatus  of  nose,  268 


INDEX 


315 


Inferior  mesenteric  artery,  113 

thyroid  veins,  124 

turbinated  bones,  29 

vena  cava,  120,  128 
Infracostales  muscle,  70 
Infra-orbital  nerve,  221 
Infraspinatus  muscle,  70 
Inguinal  glands,  233 

muscles,  76 

region,  left,  178 

right,  178 

Inner  canthus,  258 

malleolus,  40 
Innominate  artery,  99 

veins,  120,  127 
Insalivation,  157 
Insertion  of  muscles,  53 
Intercostal     arteries,     posterior, 
III 

artery,  superior,  107,  iii 

muscles,  68 

nerves,  226 

spaces,  32 
Intermaxillary  muscles,  59 
Internal  annular  ligament,  84 

carotid  artery,  103,  214 

coat  of  arteries,  95 

ear,  264 

iliac  artery,  115 
vein,  128 

intercostal  muscle,  68 

jugular  vein,  120,  123 

mammary  artery;  106 

maxillary  artery,  102 
vein,  121 

musculocutaneous  nerve,     229 

oblique  muscle,  67 

plantar  nerve,  228 

popliteal  nerve,  228 

pterygoid  muscle,  60 

saphenous  vein,  120 
Intervertebral  foramina,  204 


Intestinal  digestion,  170 

juice,  172 
Intestines,  165 
large,  165,  168 
small,  165 
coats  of,  167 
lymphatics  of,  170,  173 
villi  of,  167,  170 
villous  coat  of,  167 
Involuntary  micturition,  18I 

muscles,  55 
Iris,  253,  255 
Irregular  bones,  20 
Ischium,  34 

tuberosity  of,  34 
Island  of  Reil,  213 

Jaws,  bones  of,  27-30 

muscles  of,  58,  59 
Jejunum,  166 
Joints,  42 

ball-and-socket,  45,  46 

biaxial,  45 

condyloid,  45 

gliding,  45,  46 

hinge,  45 

pivot,  45 

polyaxial,  45 

saddle,  45 

uniaxial,  45 
Jugular  vein,  anterior,  123 
external,  120,  123 
internal,  120,  123 

Katabolism,  181 
Kidneys,  182 

blood-supply  of,  185 

capsule  of,  183 

cortex  of,  183 

glomerulus  of,  183 

medulla  of,  183 

structure  of,  183 


3i6 


INDEX 


Kidneys,  uriniferous  tubules  of, 
183,  184 
waste  products  eliminated  by, 
181,  182 
Knee,  house-maids',  41 
Knee-cap,  40 
Knee-joint,  ligaments  of,  43 

Labia  majora,  272 

minora,  272 
Labyrinth,  264 
Lacrimal  fistula,  260 

glands,  244 
Lactation,  247 
Lacteals,  170,  173 
Lacus  lachrymalis,  258 
Lamellae,  13 

Large  intestine,  165,  168 
Larynx,  144 

Latissimus  dorsi  muscle,  64 
Left  azygos  vein,  120 

common  carotid  artery,,  99 

coronary  artery,  98 

hypochondriac  region,  178 

inguinal  region,  178 

lumbar  region,  1 78 
Leg,  bones  of,  38,  40 

muscles  of,  78,  79,  82 

veins  of,  126 
deep,  126 
Lens,  256 

capsule  of,  257 
Leukocytes,  134 
Leukocytosis,  134 
Levator  costarum  muscle,  68 

labii  muscle,  59 

palati  muscle,  62 

palpebrae  muscle,  57 
Lieberkuhn,  glands  of,  172 
Ligamenta  dentata,  217 
Ligaments,  44 

annular,  84 


Ligaments  of  foot,  44 

of  knee-joint,  43 

of  ovaries,  280,  281,  284 

of  shoulder,  42 

of  uterus,  278 

of  wrist-joint,  43 

round,  285 

sutural,  42 
Ligamentum  denticulatum,  203 
Line  of  bones,  20 
Linea  alba,  67 
Lingual  artery,  100 

bone,  30 
Lingualis  muscle,  62 
Liquor  sanguinis,  132 
Liver,  235 

blood-supply  of,  236 

color  of,  236 

function  of,  236 
Lobules  of  testicles,  288 
Long  bones,  20 
Longus  colli  muscle,  64 
Lower  extremities,  bones  of,  38, 
39 
muscles  of,  76 
veins  of,  126 
Lumbar  arteries,  114 

ganglia,  231 

nerves,  226 

plexus,  226 

region,  left,  178 
right,  178 

vertebrse,  22 
Lumbricales  muscle,  76 
Lungs,  145 

breathing  air  in,  150 

color  of,  146 

complementary  air  in,  150 

of  fetus,  140 

relations  of,  146 

reserve  air  in,  150 

residual  air  in,  150 


INDEX 


317 


Lungs,  shape  of,  146 

situation  of,  145 

substance  of,  146 

supplemental  air  in,  150 

tidal  air  in,  150 

waste  products  eliminated  by, 
181 

weight  of,  147 
Lymph,  173 
Lymphatic  glands,  233 

of  small  intestine,  170,  173 

Malar  bones,  28 
Malleolus,  inner,  40 
Malleus,  262 
Malpighian  bodies,  183 
Mammary  artery,  internal,  106 
glands,  246 
acini  of,  247 
areola  of,  246 
changes  in,  247 
lactation,  247 
structure  of,  247 
Manubrium  of  sternum,  30 
Marrow,  16 
Masseter  muscle,  59 
Mastication,  156 

nerves  involved  in,  157 
Mastoid  cells,  262 
Matrix  of  nail,  196 
Maxillary  artery,  internal,  102 
bone,  inferior,  29 

superior,  27 
muscles,  inferior,  59 

superior,  58 
nerve,  inferior,  221 

superior,  221 
vein,  internal,  121 
Meatus,  external  auditory,  262 
of  nose,  268 
urinarius,  187 
Median  basilic  vein,  125 


Median  cephalic  vein,  125 

vein,  125 
Mediastinal     arteries,   posterior, 

III 
Mediastinum,  145,  152 
Medulla  oblongata,  198-200,  213 
functions  of,  207 

of  kidney,  183 
Medullary  artery,  17 

portion  of  cerebrum,  199,  211 
Meibomian  glands,  259 
Membrana  tympani,  262 
Membranes  of  body,  251 

of  brain,  198,  209 

of  spinal  cord,  216 
Meningeal  arteries,  215 

artery,  anterior,  104,  215 
middle,  215 
posterior,  215 
Menstrual  periods,  284 
Menstruation,  uterus  after,  277 

during,  277 
Mesenteric  artery,  inferior,  113 
superior,  113 

glands,  233,  245 
Mesentery,  165 
Metabolism,  180,  181 
Metacarpus,  38 
Metatarsal  bones,  42 
Micturition,  187 

involuntary,  188 
Middle  cerebral  artery,  214 

coat  of  arteries,  95 

constrictor  muscle,  63 

meatus  of  nose,  268 

meningeal  artery,  215 

temporal  artery,  102 
Mineral  salts  of  blood,  136 
Mitral  valve,  89,  90 
Mixed  nerves,  208 
Monro,  foramen  of,  212 
Mons  veneris,  272 


318 


INDEX 


Morsus  diaboli,  280 
Motion,  nerves  of,  207 
Motor  oculi  nerves,  219 
Mucous  membrane,  251 

of  nose,  266 
Mumps,  242 
Muscles,  52 

auricular,  57 

contractility  of,  53,  54 

diaphragmatic,  68 

femoral,  77,  80,  82 

gluteal,  80 

iliac,  76 

inferior  maxillary,  59 

inguinal,  76 

insertion  of,  53 

intermaxillary,  59 

involuntary,  55 

irritability  of,  54 

maxillary,  58 

nasal,  58 

non-striped,  55 

number  of,  53 

occipital,  55 

of  abdomen,  66 
action,  67 

of  back,  64 

of  face,  55 

of  foot,  79,  84 

of  forearm,  72 

of  hand,  74 

of  head,  55,  56 

of  hip,  77 

of  jaws,  58,  59 

of  leg,  78,  79,  82 

of  lower  extremities,  76 

of  neck,  56,  60,  61 

of  nose,  58 

of  orbit,  57 

of  palate,  62 

of  perineum,  84,  85 

of  thigh,  78 


Muscles  of  thorax,  68 

of  trunk,  64-66 

of  upper  extremities,  69 

orbital,  59 

palpebral.  57 

pharyngeal,  62 

pterygoid,  60 

pterygomaxillary,  60 

sheath  of,  53 

size  and  form,  53 

striped,  55 

superior  maxillary,  58 

temporomaxillary,  59 

voluntary,  55 
Muscular  system,  52 
Muscules,  origin  of,  53 
Musculocutaneous  nerve,  229 
Myocardium,  88 
Myology,  definition,  12 
Myopia,  261 

Nails,  192,  195 
Nameless  bones,  34 
Nares,  anterior,  267 

posterior,  267 
Nasal  bones,  27 

fossae,  267 

duct,  260 

muscles,  58 
Neck,  big,  244 

ganglia  of,  230 

muscles  of,  56,  60,  61 

of  femur,  40 

veins  of,  121,  122 
Nerves,  198,  203,  219 

cranial,  219 

functions  of,  207 

involved  in  mastication,  157 

mixed,  208 

of  bones,  17 

of  general  sensation,  207 

of  motion,  207 


INDEX 


319 


Nerves  of  organic  life,  229 

of  special  sensation,  207 

sacral,  228 

spinal,  203,  224 

sympathetic,  208,  229,  230 
Nervous  membrane  of  retina,  256 

system,  198 

functions  of,  206 
Neurilemma,  203,  217 
Neurology,  definition,  12 
Ninth  cranial  nerve,  222 
Nipple,  246 

Non-striped  muscles,  55 
Nose,  266 

bones  of,  27,  266 

fibrocartilages  of,  266 

fossae  of,  267 

meatus  of,  268 

mucous  membrane  of,  266 

muscles  of,  58 

septum  of,  268 
Nostrils,  267 
Nutrition,  291 

Oblique  muscles,  66,  67 
Obturator  externus  muscle,  8r 

internus  muscle,  81 

nerve,  227 
Occipital  artery,  loi 

bone,  25 

muscles,  57 

vein,  122 
Occipitofrontalis  muscle,  55 
Ocular  arteries,  104 
Olecranon,  37 
Olfactory  nerve,  219 
Olivary  bodies,  214 
Omohyoid  muscle,  61 
Ophthalmic  artery,  104 

nerve,  221 
Opponens  minimi  digiti  muscle, 

76 


Opponens  pollicis  muscle,  75 
Opsonin,  135 
Optic  lobes,  213 

nerve,  219 

thalamus,  212 
Orbicularis  oris  muscle,  59 

palpebrarum  muscle,  57 
Orbit,  29 

muscles  of,  57 
Orbital  arteries,  102,  104 
Organs  of  sight,  253 

of  special  sense,  253 
Os  calcis,  42 

Ossa  innominata,  23,  34 
Osseous  system,  13 
Osteoblasts,  18,  19 
Osteology,  13 

definition,  12 
Ostium  abdominale,  280 

internum,  280 
Outer  canthus,  258 
Ovarian  arteries,  114 
Ovaries,  280 

arteries  of,  285 

blood-supply  of,  285 

ligaments  of,  280,  281,  284 

nerves  of,  285 

veins  of,  285 
Oviducts,  279 
Ovum,  283 

discharge  of,  283 
Oxidation,  297 

bodily,  297 
Oxygen  carriers,  133 

Pai^ate  bones,  28 

muscles,  62 
Palatoglossus  muscle,  62 
Palatopharyngeus  muscle,  62,  63 
Palmar  interossei  muscle,  76 
Palmaris  brevis  muscle,  75 

longus  muscle,  72 


320 


INDEX 


Palpebrse,  258 
Palpebral  muscles,  57 
Pampiniform  plexus,  285 
Pancreas,  241 
Pancreatic  juice,  171,  241 

function  of,  171 
Papillae  of  eyelids,  258 

of  skin,  192 

of  tongue,  266 
Paraglobulin  of  blood,  136 
Parietal  bones,  25 
Parotid  arteries,  102 

glands,  241 
Parotitis,  epidemic,  242 
Parturition,  uterus  after,  277 
Patella,  40 
Pathetic  nerve,  219 
Pavilion  of  ear,  261 
Pectineus  muscle,  80 
Pectoralis  major  muscle,  69 

minor  muscle,  69 
Pelvis,  30,  32 

brim  of,  32 

cavity  of,  32 

outlet  of,  33 
Penis,  287 

Pericardiac  arteries,  1 1 1 
Pericardium,  88,  251 
Perimysium,  52 
Perineum,  84 

muscles  of,  84,  85 
Periosteum,  14,  18 
Peristalsis,  170 
Peritoneum,  251 
Permanent  teeth,  160 
Perspiration,  296,  299 

uses  of,  300 
Peyer's  patches,  168 
Phagocytes,  135 
Phagocytosis,  135 
Phalanges  of  foot,  42 

of  hand,  38 


Pharyngeal     artery,     ascending, 
102 

muscles,  62 
Pharynx,  63 
Phrenic  arteries,  112 
Physiologic  constants,  table  of, 

303-305 
Physiology  of  vision,  260 
Pia  mater,  199,  210,  217 

testis,  289 
Pigmentum  nigrum,  255 
Pinna,  261 

Pituitary  membrane,  268 
Pivot  joints,  45 
Placenta,  141 
Plantar  nerve,  228 
Plasma  of  blood,  132,  135 
Platysma  myoides  muscle,  60 
Pleura,  152,  251 
Pleural  cavity,  152 

membrane,  145 
Plexus,  203 

axillary,  225 

brachial,  225 

lumbar,  226 

pampiniform,  285 

preaortic,  230 

prostatic,  128 

sacral,  228 

uterine,  128 

vesical,  128 

visceral,  230 
Pneumogastric  nerve,  222 
Polyaxial  joints,  45 
Pons  varolii,  213 
Popliteal  artery,  116 

nerve,  external,  228 
internal,  228 

vein,  126 
Pores  of  skin,  249 
Portal  circulation,  130 

veins,  130 


INDEX 


321 


Posterior  auricular  artery,  102 
vein,  122 

cerebral  arteries,  215 

chamber  of  eye,  256 

crural  nerve,  228 

cutaneous  nerve,  227 

fontanel,  26 

horns  of  spinal  cord,  219 

intercostal  arteries,  1 1 1 

mediastinal  arteries,  1 1 1 

meningeal  artery,  215 

nares,  267 

tibial  artery,  118 

ulnar  vein,  124 
Potts'  fracture,  40 
Power  of  accommodation,  261 
Preaortic  plexus,  230 
Pregnancy,  uterus  during,  277 
Prepuce,  288 
Presbyopia,  261 
Prevertebral  sympathetic  nerve, 

229 
Profunda  cervicis  artery,  107 
Pronator  quadratus  muscle,  73 

teres  muscle,  72 
Prostate  gland,  287 
Prostatic  plexus,  128 

sinus,  287 
Proteids  of  blood,  135 
Protoplasm,  134 
Psoas  magnus  muscle,  76 

parvus  muscle,  77 
Pterygoid  artery,  103 

muscles,  60 
Pterygomaxillary  muscles,  60 
Ptyalin,  157 
Puberty,  uterus  at,  277 
Pubes,  34 
Pudendum,  271 
Pulmonary  artery,  130 

circulation,  130 

transpiration,  296 

21 


Pulmonary  veins,  131 
Pupil,  255 

Pyloric  orifice  of  stomach,  162 
Pyrif ormis  muscle,  8 1 

Quadratus  femoris  muscle,  81 

Rachitis,  bones  in,  15 
Radial  artery,  109 

vein,  125 
Radiating  fibers  of  iris,  255 
Radius,  37 
Ranine  artery,  100 
Receptaculum  chyli,  173 
Rectum,  169 

Rectus     capitis     anticus     major 
muscle,  64 
minor  muscle,  64 

femoris  muscle,  79 

lateralis  muscle,  64 
Red  corpuscles    132,  133 
composition  of,  133 
function  of,  133 
Reil,  island  of,  213 
Renal  arteries,  114 
Repair  of  body,  294 
Reserve  air  in  lungs,  150 
Residual  air  in  lungs,  150 
Respiration,  147 

accessory  organs  of,  151 

air  taken  into  lungs  in,  148 

bronchi  in,  151 

trachea  in,  151 
Respiratory  center,  152 

quotient,  149 

system,  144 
Restiform  bodies,  214 
Retina,  256 
Retrahens,  57 
Ribs,  31,  153, 

false,  31 

floating,  31 


322 


INDEX 


Ribs,  spaces  between,  32 

true,  31 

vertebral,  31 

vertebrocostal,  31 
Rickets,  bones  in,  15 
Ridge  of  bones,  20 
Right  azygos  vein,  1 20 

common  carotid  artery,  99 

coronary  artery,  98 

hypochondriac  region,  177 

inguinal  region,  178 

lumbar  region,  178 
Risorius  muscle,  59 
Rouleaux,  134 
Round  ligaments,  285 

Sacra  media,  114 
Sacral  ganglia,  231 

nerves,  228 

plexus,  228 

vertebrae,  22 
Sacrum,  33 
Saddle  joints,  45 
Saliva,  157,  241 

in  mastication,  156 
Salivary  duct,  242 
Salts,  mineral,  of  blood,  136 
Saphenous  vein,  internal,   120 
long,  127 
short,  127 
Sartorius  muscle,  78 
Scalenus  anticus  muscle,  64 

medius  muscle,  64 

posticus  muscle,  64 
Scapula,  34 
Scarf-skin,  191 

Schneiderian  membrane,  268 
Sciatic  nerve,  228 
Sclerotic  coat  of  eye,  253 
Scrotum,  288,  290 
Sebaceous  glands,  192,  194,  247 
Sebum,  247 


Second  cranial  nerve,  219 
Secretory  glands  of  skin,  192 
Segmentation,  292 
Semen,  291 

Semicircular  canals  of  ear,  264 
Semilunar  valve,  89,  91,  96 
Semimembranosus  muscle,  82 
Seminal  vesicles,  290 
Seminiferous  tubules,  289 
Semitendinosus  muscle,  82 
Sensation,  nerves  of,  207 
Septum  of  nose,  268 
Serous  membranes,  251 
Serpentine  artery,  1 1 3 
Serratus  magnus  muscle,  69 
Serum  of  blood,  136 
Seventh  cranial  nerve,  221 
Sheath  of  arteries,  96 

of  muscle,  53 
Shin  bone,  40 
Short  bones,  20 
Short-sightedness,  261 
Shoulder  girdle,  34 

ligaments  of,  42 
Shoulder-blade,  34  • 
Sight,  organs  of,  253 
Sigmoid  cavity,  37 

flexure,  169 

notch,  30 
Sinus  pocularis,  287 

prostatic,  287 
Sinuses,  121 

of  brain,  215 
Sixth  cranial  nerve,  221 
Skeleton,  13,  21 
Skin,  190 

appendages  of,  194 

bronzed,  190 

glands  of,  192 

layers  of,  191 

papillae  of,  192 

pores  of,  249 


INDEX 


323 


Skin,  scarf-,  191 

secretory  glands  of,  192 
true,  191 

waste  products  eliminated  by, 
181,  182 
Skull,  24 

bones  of,  24 
Small  intestine,  165 
coats  of,  167 
lymphatics  of,  170,  173 
villi  of,  167,  170 
villous  coat  of,  167 
Smell,  organs  of,  266 
Soft  spot,  26 
Specific  gravity  of  blood,   132 

of  urine,  188 
Spermatic  arteries,  114 

cord,  290 
Spermatozoa,  291 
Sphenoid  bones,  27 
Spinal  accessory  nerve,  224 
column,  22 
atlas  of,  23 
axis  of,  23 
curves  of,  25 
length  of,  23 
regions  of,  22 
cord,  201,  216,  217 
columns  of,  202,  218 
fissures  of,  218 
functions  of,  207 
gray  commissure  of,  219 
horns  of,  219 
membranes  of,  216 
nerves  of,  203,  224 
nerves,  203,  224 
veins,  129 
Spine,  22.     See  also  Spinal  col- 
umn. . 
bones  of,  22 
of  bone,  20 
of  scapula,  34 


Splanchnology,  definition,  12 
Spleen,  237 

function  of,  238 
Splenic  artery,   113 
Spongy  bones,  268 
Stapes,  262 
Steapsin,  171,  172 
Sternocleidomastoid  muscle,  60 
Sternomastoid  artery,  102 
Sternothyroid  muscle,  61 
Sternum,  30 
Stomach,  162 

coats  of,  162 

openings  of,  162 
Striped  muscles,  55 
Styloglossus  muscle,  62 
Stylohyoid  muscle,  62 
Stylopharyngeus  muscle,  63 
Subanconeus  muscle,  71 
Subarachnoidean  spaces,  210 
Subclavian  artery,  104 

vein,  120,  126 
Subclavius  muscle,  69 
Subcrureus  muscle,  8© 
Sublingual  glands,  243 
Submaxillary  glands,  243 
Subscapularis   muscle,  69 
Succus  entericus,  172 
Sudorific  glands,  192,  300 
Sudoriparous  glands,  249 
Sulci  of  cerebrum,  210 
Supercilia,  258 
Superior  constrictor  muscle,  63 

dental  nerve,  221 

epigastric  artery,  106 

intercostal  artery,  107,  iii 

maxillary  bones,  27 
muscles,  58 
nerve,  221 

meatus  of  nose,  268 

mesenteric  artery,  113 

thyroid  artery,  100 


324 


INDEX 


Superior  vena  cava,  120,  127 
Supinator  brevis  muscle,  74 

longus  muscle,  73 
Supplemental  air  in  lungs,  150 
Suprarenal  arteries,  1 1 4 

capsules,  190 
Supraspinatus  muscle,  70 
Surgical  neck  of  humerus,  37 
Sutural  ligament,  42 
Swallowing,  160 
Sweat,  300 

glands,  192,  193,  249 
Sympathetic    nerve,     208,     229, 

230 
Symphysis  pubis,  34 
Syndesmology,  definition,  12 
Synovia,  252 
Synovial  membrane,  44,  45,  252 

Tact,  268 

Tarsal  cartilages,  258 

Tarsus,  41 

Taste,  organs  of,  264 

Teeth,  159 

permanent,  160 

temporary,  159 
Tegumentary    areolar    tissue    of 

eyelids,  258 
Temperature  of  blood,  132 
Temporal  artery,  102 
middle,  102 

bones,  27 
of  infant,  26 

muscle,  59 

vein,  121 
Temporary  teeth,  159 
Temporomaxillary  muscle,  59 

vein,  121 
Tendons,  46,  53 
Tensor  palati  muscle,  62 

tarsi  muscle,  57 

vaginae  femoris  muscle,  77 


Tenth  cranial  nerve,  222 
Tentorium  cerebelli,  198 
Teres  major  muscle,  71 

minor  muscle,  71 
Testes,  288 
Testicles,  288 
Thigh,  muscles  of,  78 
Thigh-bone,  38 
Third  cranial  nerve,  219 
Thoracic  aorta,  97,  110 

cavity,  30 

duct,  175 
Thorax,  30 

muscles  of,  68 
Thread  of  tongue,  243 
Thyrohyoid  muscle,  61 
Thyroid  artery,  superior,  100 

axis,  107 

gland,  244 

veins,  inferior,  124 
Tibia,  40 

Tibial  artery,  anterior,  1 16 
posterior,  118 

nerve,  anterior,  229 

veins,  126 
Tibialis  anticus  muscle,  83 
Tidal  air  in  lungs,  150 
Tissue,  erectile,  288 
Tongue,  264 

bridle  of,  243 

frenum  of,  243 

nerve  supply  of,  264 

papillae  of,  266 

thread  of,  243 
Torticollis,  61 
Touch,  organs  of,  268 
Trachea,  145,  146 

in  respiration,  151 
Transpiration,  cutaneous,  296, 299 

pulmonary,  296 
Transverse  aorta,  97 

colon,  169 


INDEX 


325 


Transverse  facial  artery,  102 
Trapezius  muscle,  64 
Tree  of  life,  213 
Triangularis  sterni  muscle,  68 
Triceps  extensor  cubiti  muscle,  7 1 
Tricuspid  valve,  89,  90 
Trifacial  nerve,  220 
Trisplanchnic  nerve,  208 
Trochanters,  40 
True  ribs,  31 

skin,  191 
Trunk,  muscles  of,  64-66 

veins  of,  127 
Trypsin,  172 
Tubercle  of  bone,  20 

of  eyelids,  258 
Tubercula  quadrigemina,  213 
Tuberosity,  20 

of  humerus,  37 

of  ischium,  34 
Tunica  albuginea,  289 

vaginalis  externus,  289 

vasculosa,  289 
Turbinated  bones,  268 

inferior,  29 
Twelfth  cranial  nerve,  224 
Tympanic  artery,  103 

membrane,  262 
Tympanum,  262 

UlvNA,  37 

Ulnar  artery,  109,  no 
vein,  anterior,  124 
posterior,  124 
Umbilical  arteries,  141 
region,  178 
veins,  138,  141 
Uniaxial  joints,  45 
Upper  extremities,  bones  of,  34, 
35 
muscles  of,  69 
veins  of,  124 


Urea  in  urine,  189 
Ureters,  186 
Urethra,  187 
Urine,  188 

character  of,  188 

color  of,  188 

composition  of,  189 

constituents  of,  abnormal,  189 
normal,  189 

quantity  of,  189 

reaction  of,  188 

transparency  of,  188 

urea  in,  189 
Uriniferous    tubules    of    kidney, 

183,  184 
Urinosexual  opening,  272 
Uterine  plexuses,  128 
Uterus,  275 

after  menstruation,  277 

after  parturition,  277 

appendages  of,  279 

at  puberty,  277 

blood-supply  of,  277 

body  of,  276 

cavity  of,  278 

cervix  of,  276 

coats  of,  276 

during  menstruation,  277 
pregnancy,  277 

fetal,  277 

fundus  of,  276 

in  old  age,  278 

ligaments  of,  278 

masculinus,  287 

nerves  of,  277 

situation  of,  277 

size  of,  277 

structure  of,  276 
Uvea,  255 

Vagina,  274 

Vaginal  synovial  membranes,  252 


326 


INDEX 


Vagus  nerve,  222 
Valves  of  heart,  89 

of  veins,  119 
Vas  deferens,  289 
Vasa  vasorum,  96 
Vascular  membrane  of  retina,  256 

system,  87 
of  fetus,  138 
Vastus  externus  muscle,   79 

internus  muscle,  80 
Veins,  118 

blood  in,  120 

classification  of,  120 

of  arm,  124,  125 
deep,  125 
superficial,  124 

of  head,  121 

of  leg,  126 
deep,  126 

of  lower  extremities,  126 

of  neck,  121,  122 

of  trunk,  127 

of  upper  extremities,  124 

valves  of,  119 
Velum  interpositum,  210,  212 
Vena  azygos  major,  128 

cava,  inferior,  120,  128 
superior,  120,  127 
Venae  comites,  124 

Galeni,  212 
Venous  circulation,  119 

system,  118 
Ventilation,  coefficient  of,  151 
Ventricles,  88,  89 

of  brain,  212 
Vermiform  appendix,  168 
Vernix  caseosa,  247 
Vertebrae,  22,  23 
Vertebral  artery,  106,  214 


Vertebral  column,  22.     See    also 
Spinal  column. 

muscles,  anterior,  64 

ribs,  31 

sympathetic  nerve,  229 

vein,  123,  129 
Vertebrocostal  ribs,  31 
Verumontanum,  287 
Vesical  plexus,  128 
Vesicles,  Graafian,  281,  282 

seminal,  290 
Vestibular  nerve,  222 
Vestibule  of  ear,  264 
Villi  of  small  intestine,  167,  170 
Villous   coat  of  small   intestine, 

167 
Visceral  plexus,  230 
Vision,  physiology  of,  260 
Vitreous  humor,  253,  257 
Voluntary  muscles,  55 
Vomer,  27,  29 
Vulva,  271 

Waste,  bodily,  294 

products,  channels  of  elimina- 
tion, 181,  182 
elimination  of,  181 
Wax  of  ear,  262 
White  corpuscles,  132,  134 

of  eye,  254 
Willis,  circle  of,  214,  215 
Windpipe,  146 
Wormian  bones,  22 
Wrist-joint,  ligaments  of,  43 
Wry-neck,  61 

Xiphoid  appendix,  30 

Zygomatic  arch,  28 


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DATE  DUE  SLIP 

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1938 


OFC  1  7  1942 


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